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PREVENTIVE MEDICINE AND HYGIENE
PREVENTIVE MEDICINE AND HYGIENE
BY «
MILTON J. ROSENAU
PROFESSOR OF I'REVK NTIVF. .'MKniCINF, AND lIYCilKNE, IIAUVAIil); DIKECTOlt OF TIIK SCHOOL
OF PUBLIC HEALTH OF HARVARD UNIVERSITY AND THE MASSACHUSETl'S INSTITUTE
OF TECHNOLOGY; FORMERLY DIRECTOR OF THE HYGIENIC LABORATORY,
U. S. PUBLIC HEALTH SERVICE, ETC.
WITH CHAPTERS UPON
SEWAGE AND GARBAGE, BY GEORGE C. WHIPPLE, PROFESSOR OF SANITARY^ ENGINEERING,
HARVARD
VITAL STATISTICS, BY JOHN W. TRASK, ASSISTANT SURGEON-GENERAL, U. S. PUBLIC HEALTH
SERVICE
MENTAL HY'GIENE, BY' THOMAS W. SALMON, MEDICAL DIRECTOR, NATIONAL COMMITTEE FOR MENTAL HYGIENE, ETC.
FOURTH EDITION
NEW YORK AND LONDON D. APPLETON AND COMPANY
1921
Q^_
COPYRIGHT, 1913, 1916, 1917, 1921, by D. APPLETON AND COMPANY
PltlXTED IN THE rXlTED STAT1!S or AMERICA
TO MY WIFE
Digitized by tine Internet Arciiive
in 2010 witii funding from
Open Knowledge Commons
http://www.archive.org/details/preventivemediciOOrose
PREFACE TO THE EIKJST EDITION
This l)0()k has been written in response to a demand for a treatise based upon in(i(h>ni i)rogress in hygiene and sanitation. Tlie work is pbiiiiii'd to iiicliide those fiehls of the medical and related seienees which form the fomidation of public health work. So far as 1 know, no other book on the subject covers the broad field considered in this volume. The prog-ress in hygiene and sanitation has been so rapid that the subject of preventive medicine has become a specialty, and its scope has become so broad that the question throughout the making of this book has been rather what to leave out than what to include. The facts here brought together are widely scattered in the literature and many of them are difficult of access : they have been collected for the convenience of the student of medicine and the physician, as well as those engaged in sanitary engineering or public health work.
During twenty-three years of varied experience in public health work it has been my good fortime to have served as quarantine officer, in epidemic campaigns, in epidemiological investigations, and in public health laboratories, at home, on the Continent, and in the tropics. The fruits of these experiences are reflected in this book, which may be taken as representing my personal views gained in the field, in the laboratory, in the classroom, and in administrative offices.
It is Mell-nigh impossible to prevent or suppress a communicable disease without a knowledge of its mode of transmission. This is the most important single fact for successful personal prophylaxis, as well as in the general warfare against infection; therefore the com- municable diseases have been grouped in accordance with their modes of transference'. Each one of the important communicable diseases is dis- cussed separately in order to bring out the salient points upon which prevention is based. The classification adopted is believed to be unique and should prove helpful to tJiose who are especially concerned in the prevention of infection.
The book may be considered in two parts, namely, that which deals with the person (hygiene) and that which deals with the environment (sanitation). The first part includes the prevention of the communicable diseases, A'enereal prophylaxis, heredity, immunity, eugenics, and similar subjects. The second part deals with our environment in its relation to health and disease and includes a discussion of food, water, air, soil, disposal of wastes, vital statistics, diseases of occupation, industrial
vii
viii PREFACE TO THE FIRST EDITION
hygiene, school hygiene, disinfection, quarantine, isolation, and other topics of sanitary importance, as well as subjects of interest to health officers. All the important methods used in public health laboratories are described.
To have made this book in monographic style with references to authorities for every statement would have resulted in an un^^^eldy work of impractical size and form. The textbook style has therefore been adopted and citation of authorities for facts that are now well estab- lished has been regarded as unnecessary. In this respect it may seem that I have given scant credit to many workers from whose writings I have borrowed results, thoughts, and sometimes words or even sen- tences. At the end of each chapter will be found a list of references to articles or books that I have especially drawn upon, and I desire to acknowledge my obligations to these sources as well as to refer the reader to them for further study of particular subjects. I have also draAvn freely upon my own previous writings and those of my co-workers in coriipiling this book. The chapter on "Disinfection"' is based upon my book entitled : "Disinfection and Disinfections." published by P. Blaki- ston's Sons & Co., Philadelphia, 1902.
I have received generous help from a number of friends and it is a pleasure here to acknowledge especially my obligation to Dr, David L. Edsall for reading and correcting the chapter on Diseases of Occupa- tions, to Dr. John F. Anderson and Dr. Joseph Goldberger for re- vising the chapters upon Measles and Typhus Fever, to Prof. George C. Whipple for reading and improving the chapter upon "Water, to Charles T. Brues for many suggestions in the section upon insect-borne diseases, and to Prof. W. E. Castle for a similar service with the section on Heredity. Dr. Charles Wardell Stiles has kindly furnished infor- mation concerning the relation of parasites to soil. I also desire to express my obligations to Prof. Arthur I. Kendall, Dr. Harold L. Amoss, Dr. Lewis W. Hackett, Prof. William D. Frost, and Miss Emily G. Philpotts.
It has "been my object to give in this volume the scientific basis upon which the prevention of disease and the maintenance of health must rest. Exact knowledge has taken the place of fads and fancies in hygiene and sanitation; the capable health officer now possesses facts concerning infections which permit their prevention and even their suppression in some instances. Many of these problems are complicated with economic and social difficulties, which are given due consideration, for preventive medicine has become a basic factor in sociology.
M. J. ROSEXAU BoSTOjST
PREFACE TO THE FOURTH EDITION
This edition has been largely rewritten and entirely reset. The fol- lowing new snbjects have been added : Public Health Methods and Measures; Relative Values in Public Health Work; A Public Health Program; Organization of Health Departments; Median Endemic Index; Housing; Rural Sanitation; Public Health Education; Public Health .Xursing: Drug Addiction, Alcoholism; Undernutrition; Sani- tary Surveys; Infant Mortality; Koch's Laws; Intelligence Quotient; Vitamins : Oral Hygiene ; Ocular Hygiene ; Personal Hygiene ; and a Laboratory Course in Preventive Medicine and Hygiene.
The following diseases are discussed in this book for the first time: Vincent's Angina; Deer-Fly Fever; Leishmaniasis; Epidemic Encepha- litis; Yaws; Psychoneuroses ; War Edema.
The following subjects have been rewritten : Venereal Diseases and Hygiene of Sex ; Dysentery ; Influenza ; Trench Fever ; Mental Defec- tives; Food Poisoning; Botulism; Deficiency Diseases and Goiter. More or less extensive changes have been made throughout the rest of the volume.
I have received letters from many parts of the world calling my attention to errors of commission or omission. I am grateful for these suggestions and will appreciate others that may help improve the book and keep it up to date. Acknowledgment of special help is stated on page xi.
M. J. ROSENAU
Hakvabd Medical School Boston
ACKNOWLEDGMENTS
In making this l.o(.l^ 1 liavo enjoyed assistance from many friends. J am especially indebted to the i■ollo^vino• fur heli) in the subjects named :
1)K. J. 1*. Lkake, Smallpox and \aecination
Dk. a. i\I. Stimson, Rabies
Di{. W. A. HiNTOX, Glanders, The Wasscrmanii Eeaction
Dk. F. n. Yekiioeff, Preventable Blindness, Ocular Hygiene
Dr. a. W. Sellards, Dysentery
Dr. E. K. Tyzzei!, Leishmaniasis
Dr. a. K. Krause, Tuberculosis
Dr. E. H. Place, Diphtheria, Scarlet Fever, Measles, Whooping Cough
Dr. Eufus Cole, Pneumonia
Dr. C. W. Stiles, Hookworm Disease
Dr. B. H. Eansom, Intestinal Parasites
Dr. H. E. Carter, Mosquitoes, Malaria
Dr. L. 0. Howard, Flies
Dr. FJarry Plotz, Lice, Typhus Fever
Dr. G. W. McCoy, Leprosy, Anthrax
Dr. E. H.' Creel^ Maritime Quarantine
Dr. J. Broxfexbrenner, Immunity
Dr. J. E. Mohler, Meat Inspection
Dr. J. GoLDBERGER, Pellagra
Dr. C.-E. a. WmsLOW, Ventilation
Dr. Alice Hamilton, Industrial Hygiene
Dr. G. C. Whipple, Sewage, Garbage and Eefuse
Dr. J. W. Trask, Vital Statistics
Dr. T. W. Salmon, Mental Hygiene
Lieutenant Colonel C. F. Foster, Major J. E. Bayliss, Major E. E. Hume and Major G. F, Lull read and corrected the chapter on Military Hygiene. My colleagues, Dr. M. J. Schlesinger, Dr. Harry Weiss, Dr. D. L. Sisco, Dr. Benjamin White, Mr. E. W. Lamson, and Mr. A. P. Pratt, helped me see the book through the press. My efficient secretary, Miss Mae C. Moran, made the index.
D. Appleton and Company have met with unusual difficulties in publishing a book of this size at this time, and I am indebted for their cooperation, especially that of Dr. J, E, Broome,
HARVAKD Medical School ^' ^- ^^^^NAU
Boston
CONTENTS
SECTION I PREVENTION OF THE COMMUNICABLE DISEASES
CHAPTEn '"-*'' l^-
I. DISEASES HAVING SPECIFIC OR SPECIAL PROPHYLACTIC
MEASURES 1
Smallpox and Vaccination
Historical Note, 1; Vaccination, 3; Vaccine Virus, 4; Methods of Vaccination, 9; Indices of a Successful Vaccination, 12; The Immunity, 14; Revaccination, 18; Claims for Vaccination, 20; Vaccination of Exposed Persons, 20; Dangers and Complications, 21; Tlie Government Control of Vaccine Virus, 24: The Unity of Cowpox a'nd Smallpox, 25; Compulsory Vaccination, 25; Inoculation or Variola Inoculata, 26; Prevalence of Smallpox, 28; Epidemiology, 29; Modes of Infection, 30; Resistance of the Virus, 31; Smallpox in the Vaccinated and Unvaccinated; 31; Isolation and Disinfection, 35.
Rabies :
General considerations, 38; Period of Incubation, 39; Entrance and Exit of the Virus, 40; The Relative Danger of Bites, 41; Viability, 41; Prophylaxis, 42; The Local Treatment of the Wound, 43; The Pasteur Prophylactic Treatment, 44; Diagnosis of Rabies in Dogs, 51.
Vexebeal Diseases:
Syphilis, 55; Gonorrhea, 67; Chancroid, 72.
Venereal Prophylaxis and Hygiene of Sex:
Prevalence, 73; Attitude, 75; Education, 76; Notification, 78; Continence, 79; Personal Hygiene, 79; Alcohol, 80; Prostitu- tion, 80; Segregation, 81; Medical Prophylaxis, 81; Hospitals and Clinics, 85.
Pkevextable Blixdxess:
, Ophthalmia Neonatorum, 87; Trachoma. 92: Toxic Amblyopia, 94; Accidents, 94.
Tetanus :
Etiology, 95 ; Occurrence. 97 ; Trismus Neonatorum, 99 ; Incuba- tion, 100; Resistance, 100; Prophylaxis, 102.
II. DISEASES SPREAD LARGELY THROUGH THE ALVINE DIS-
CHARGES 105
Typhoid Fever
General Considerations, 105; Historical Landmarks, 106; Prevalence. 107: Channels of Entrance and Exit, 110; Diagnosis, 110; Bacillus Carriers, 113; Resistance of the Virus, 116; Ty- ph<)id Bacillus in Nature, 117; Modes of Spread, 118; Typhoid Vaccines, 128; Management of Case, 133; Personal Prophylaxis, 135.
Paratyphoid Fever
General Considerations, 136; Paratyphoid Fever and Food Poisoning, 138.
xiv CONTENTS
CHAPTER PAGE
Choleba
General Considerations, 139; The Cause and Contributing Causes, 139; Diagnosis, 141; Modes of Transmission, 142; Bacillus Car- riers, 144 ; Immunity and Prophylactic Inoculations, 145 ; Quaran- tine, 146; Personal Prophylaxis, 147.
Dysenteky
Bacillary Dysentery, 148; Amebic Dysentery, 150; Contrast be- tween Bacillary and Amebic Dysentery, 151.
Hookworm Disease
Distribution, 153; Species of Hookworm, 154; Modes of Trans- mission, 154; The Parasite, 154; Immunity, 157; Resistance of the Parasite, 157; Prevention, 158; Plan of Campaign, 160.
III. DISEASES SPREAD LARGELY THROUGH DISCHARGES FROM
THE MOUTH AXD NOSE 163
TUBEECtXOSIS
General Considerations, 163 : The Difference between Human and Bovine Tubercle Bacilli, 165: Bovine Tuberculosis in Man.. 166; Modes of Infection, 170; Immunity, 177; Resistance of the Virus, 180; Prevention, 181; Segregation — Sanatoria, 182: Per- ' ^sonal Prophylaxis, 184; Tuberculosis in Children. 187: Bovine
Tuberculosis, 188; Directions for Testing Cattle with Tuberculin, 188; The Bang Method of Suppressing Bovine Tuberculosis, 189; Organization of a Local Tuberculosis Campaign, 190; Outlook, 191.
DlPHTHEEIA
General Considerations, 191; Modes of Transmission, 193; Bacillus Carriers, 195: Diagnosis, 198: Resistance. 198; Im- munity, 199; The Schick Reaction, 201; The Control of Out- breaks, 202; Responsibility of the Medical Profession, 206; Pre- vention of Post-diphtheritic Paralysis, 207 ; Prevention of Serum Sickness and Anaphylactic Shock, 208; Historical Note, 209.
Vincent's Angina 210
Measles
General Considerations, 212; Immunity, 213; Resistance of the Virus, 214; Modes of Transmission, 215; Prevention, 217.
German Measles 219
Scarlet Fever
General Considerations, 219; Modes of Transmission, 220; Im- munity, 223; Prophylaxis, 223.
Whoopixg-Cough
General Considerations, 224 : Modes of Transmission, 225 ; Im- munity, 226; Prevention, 226; Mortality, 228.
Mumps 228
Lobar Pneumonia
General Considerations, 230; Types of Pneumococci, 231; Resist- ance of the Virus, 232; Modes of Transmission, 232; Carriers, 233; Immunity, 2.34; Prevention, 236; Preventive Measures, 237.
Influenza
General Considerations, 239; Etiology, 241; Mode of Infection, 241; Epidemiology, 241; Vaccines, 244; Administrative Meas- ures, 245.
Common Colds '
General Considerations, 246; Prevention, 247; Drafts and Chill- ins, 248.
CONTENTS XV
CHAPTER PAGE
Cerebrospinal Fever
tk-nenil Considerations, 250; Epidemiology, 251; Modes of Transmission, '252; Carriers, 254; Prevention, 257.
IV. INSECT-BOKNE DISEASES 259
General Coxsiderations 259
Insecticides . '
General Considerations, 266; Preparation of the Room for Funii<jatii)n, 266: The Relative EHieiency of Insecticides, 267; Sulphur, 2(i!): Forinaldehyd. 270: Pyrethruni, 271: Phenol- Camphor, 272: Hydrocyanic Acid Gas, 273; Bisulphid of Car- bon, 274; Petroleum, 275; Arsenic, 276.
Mosquitoes
General Considerations, 279: Life History and Habits, 280; The Destruction of ilosquitoes, 281; Malaria, 286; Yellow Fever, 295; Dengue, 303; Filariasis, 305.
Flies
General Considerations, 307 ; Life History of the Musca Do- mestica, 309: Life History of Stomoxys Calcitrans, 310; Flies as Mechanical Carriers of Infection, 311; Suppression, 315; Sleeping Sickness, 317; Deer-Fly Fever, 321; Pappataci Fever, 322.
Fleas
General Considerations, 322; Pulicides, 325; Relation of Plague to Rats and Fleas, 325.
Rats a:sd Other Rodents
General Considerations, 328 : Breeding and Prevalence, 329 ; Migration, 330: On Vessels, 331; Food, 331; Habits, 332; Rat- Bite Fever. 332 ; Plague in Rats, 333 ; Acute Infectious Jaundice, 335; Rat Leprosy, 337; Trichinosis, 337; Food Infection. 337; Other Parasites, 337 : Economic Importance, 338 : Suppression of Rats, 338; Squirrels and Plague, 344; Plague, 345.
Ticks
General Considerations, 354; Texas Fever. 356; Rocky Moun- tain Spotted Fever, 356; Japanese River Fever, 361; Relapsing Fevers, 361.
Lice
General Considerations, 362; Lice Bites and the Transmission of Disease, 365; Delousing, 366: Lice as a ^Military Problem, 369; -Typhus Fever, 370; Trench Fever, 376.
Bedbugs
General Considerations, 378; Suppression, 379.
Leisioianiasis 380
Roaches 383
V. MISCELLANEOUS DISEASES 386
Infantile Paralysis
General Considerations, 386; Resistance of the Virus, 389; Im- munity, 390; Modes of Transmission, 390; Prevention, 392.
Epidemic Encephalitis 394
Chickenpox 395
Glanders
General Considerations, 396; Diagnosis, 397; Prevention, 400,
Anthrax
General Considerations, 401; Resistance, 402; Prevention, 402.
FOOT-AXD-MOUTH DISEASE 405
xvi CONTENTS
CHAPTER PAGE
Malta Fever
General Considerations, 407 ; Modes of Transmission, 407 ; Goats' Milk and Malta Fever, 409; Prevention, 410.
Yaws 410
Leprosy
General Considerations, 411; Immunity, 413; Rat Leprosy, 414;
Modes of Transmission, 415; Prevention, 418.
SECTION II
MENTAL HYGIENE By Thomas W. Salmon
General Considerations 421
The Problems of Mental Hygiene, 422; Heredity, 424; Alcohol, 429; Other Exogenous Poisons, 433; Endogenous Poisons, 434; Syphilis, 434; Other Infections, 437; Head Injuries, 438; Men- tal Causes, 439; Experience of the World War, 442; Economic Factors, 449; Immigration, 450.
Agencies Available for the Application of Preventive Medicine Hospitals for Mental Disease, 451 ; Public Health Authorities, 452; Educational Authorities, 452; National and Local Societies for Mental Hygiene, 452.
Conclusion 454
SECTION III PUBLIC HEALTH MEASURES AND METHODS
SOME GENERAL CONSIDERATIONS 459
Sources of Infection, 459; Modes of Transference, 460; Carriers, 462 ; Missed Cases, 463 ; Channels of Infection, 463 ; "Contagious" and "Infectious," 463; Epidemic, Endemic, Pandemic, and Prosodemic, 464; Fomites, 465.
Relative Values of Public Health Work 466
A Score for Health Activities 468
A Public Health Program 469
Organization of Health Departments 470
The Median Endemic Index 472
Health Centers . 473
Housing 473
Rural Sanitation 475
Public Health Education 476
Infant Mortality 477
Public Health Nursing • 483
Nuisances . 483
Face Masks 485
Drug Addiction 486
Alcohol 487
Sanitary Surveys . 493
Management of an Epidemic Campaign 495
Quarantine 498
General Considerations, 498; Maritime Quarantine, 502; Quaran- . tine Procedures, 509 ; The Bill of Health, 509 ; The Equipment of
a Quarantine Station, 510; Qualifications of Quarantine Officers,
CONTENTS xvii
PAGE
511; Disinfection of Ships, 511; Fumigation of Sliipp, ol.l; Cargo, 518; Foreign Inspection Service, 518; National versus State Quarantine, 51i>; Interstate Quarantine, 519.
SKCTION^ IV
IMMUNITY, HEKEDITY, AND EUGENICS
I. IMMUNITY 523
General Considerations 523
Mecluinisni of Immunity, 527; Theories of Immunity, 528;
Natural Immunity, 530; Acquired Inununity, 532; Non-Specific
Immunity, 532; iMixed Immunity, 533; How Active Imnuinity
May Be Acquired, 533; Bacterial Vaccines, 535; Specificity, 537;
Local and General Immunity, 53!); Bacillus Carriers, 540;
Latency, 542; Lowered Resistance, 542; Relation between Host
and Parasite, 546; Ehrlich's Side-Chain Theory of Immunity,
647 ; Antitoxic Immunity, 553.
Toxins 553
Antitoxins
General Considerations, 558; Preparation of Antitoxin, 561;
Method of Concentrating Diphtheria Antitoxin, 562; Mode of
Action, 563. ,
Endotoxins 565
Standardization of Antitoxic Sera
Standardization of Diphtheria Antitoxin, 566; Standardization
of Tetanus Antitoxin, 568.
Phagocytosis 570
Opsonins 574
Lysins 575
Hemolysis 578
Cytotoxins ..... 579
The Bordet-Gengou Phenomenon — Fixation of Complement The Wassermann Reaction, 581.
The Neisser-Wechsberg Phenomenon or Deviation of the Com- plement ; . 583
Precipitins
General Considerations, 585; Tests for Blood, 587.
Agglutinins 589
Anaphylaxis
General Considerations, 593; Examples of Anaphylaxis, 594; Experimental Anaphylaxis, 594; Specificity, 596; Sensitization by Feeding, 598; Maternal Transmission, 598; Serum Anaphy- laxis in Man, 598; Hypersusceptibility and Immunity Produced by Bacterial Proteins, 601; Relation of Anaphylaxis to Protein Metabolism, 602; Relation of Anaphylaxis to Endotoxins, 602; Relation of Anaphylaxis to Tuberculosis, 602; Relation of Anaphylaxis to Vaccination, 603; Relation of Anaphylaxis to Food "Idiosyncrasies," 604; Eczema, 604; Relation of Anaphy- laxis to Hay Fever, 605; Relation of Anaphylaxis to Drugs. Anaphylactoid Reactions, 605; Other Practical Relations of Anaphylaxis, 605.
II. HEREDITY AND EUGENICS 607
General Considerations 607
Defectives, 608; Recognition, 608; Mongolianism, 608; Feeble- minded— Idiots, Imbeciles and Morons, 609 ; Prevention of Propa-
xviii CONTENTS
CHAPTER P\GE
gation of Defectives, 611; Statistics of Defectives, 613; De- generate Families, 615.
Eugenics ; 619
Pbixciples of Heredity
Variation, 621; Darwin's Theory — the Survival of the Fittest, 621; Mutation, 622; DeVries — Discontinuous Evolution, 622; Weissmann's Views, 623 ; Mendel's Law, 624 ; Atavism and Rever- sion, 628; Galton's Law of Filial Regression, 629.
The Cell in Heredity 629
Statistical Methods 631
Heredity versus Environment 638
Immunity Gained through Inheritance 639
III. THE HEREDITARY TRANSMISSION OF DISEASE . . . '. 640
General Considerations 640
Inbreeding, 642; The Microbic Diseases, 643; Congenital Trans- mission, 644; Hereditary Transmission of a Tendency to a Dis- ease, 644 ; Tuberculosis, 645 ; Syphilis, 645 ; Cancer, 646 ; Leprosy, 648; Deaf -Mutism, 648; Albinism, 649; Color-Blind- ness, or Daltonism, 650; Hemophilia, 651; Gout, 651; Brachy- dactylism, 652; Polj'dactylism, 653; Fragilitas Ossium, 653; Myopia, 653; Cataract, 653; Retinitis Pigmentosa, 653; Diabetes Mellitus, 654; Orthostatic Albuminuria, 654; Alcoholism, 654; Migraine, 654; Anaphylaxis or Food Idiosyncrasies, 655; Hay Fever, 655; Epilepsy, 655; Huntington's Chorea, 655; Fried- reich's Disease — Hereditary Ataxia, 656; Mental Deficiency, 658; Insanity, 658.
SECTION V FOOD
I. GENERAL CONSIDERATIONS 661
The Uses of Food
General Considerations, 663; Caloric Value of Food, 664. Classification of Foods
Physical Properties, 666; Sources, 666; Chemical Composition,
666; Composition and Function, 667.
Vitamins 669
The Amount of Food
Excessive Amounts, 673; Insufficient Food, 674; Famine and Pestilence, 675 ; War Edema, 675 ; Underfeeding and Growth, 676.
Unbalanced Diets 676
The Deficiency Diseases
General Considerations, 677; Beriberi, 678; Scurvy, 683; Rickets, 685; Pellagra, 686.
Food Poisoning
General Considerations, 692.
Food Infections
Incubation Period, 696 ; Symptoms, 696 ; Taste, Odor and Ap- pearance, 698; Kind of Food Responsible, 698; Diagnosis, 698; The Colon-Typhoid Group, 699; The Gaertner Group, 701.
Botulism
General Considerations, 706; Prevalence, 706; Symptoms, 708; Pathology, 710; The Bacillus, 710; Toxin, 712; Antitoxin, 715; Prevention, 716.
CONTENTS xix
CHAPTER PAOE
Decomposed Foods
Geiu'ial Consiclerations, 717; Fermontation and Putrefaction, 718; I'utrefac'tive Changes in Proteins, 719; "Ptomain" Poison- ing, 721.
Adulteration of Food 725
Preservation of Foods
General Considerations, 728: Cold, 730; Drying, 733; Salting and Pickling, 735; Jellies and Preserves, 730; Smoking, 737; Canning, 737; Chemical Preservatives, 741.
The Preparation of Food
Cooking, 749; Methods of Cooking, 751.
II. ANIMAL FOODS: MILK 753
Milk
General Considerations, 753; Composition, 754; Ferments or "Life" in Milk, 760; Thermal Death Point of Milk Enzymes, 761; "Leukocytes" in Milk, 762; The Excretion of Drugs in MUk, 763; The Differences between Cow's Milk and Woman's Milk, 763; Milk Standards, 764: Grades of Milk, 765; Certified Milk, 767; "Standardized" or Adjusted Milk, 768; Pveconstructed Milk, 768; The Decomposition of Milk, 768; Sour Milk and Intestinal Flora, 769; Putrid Milk, 770; Slimy or R6py Milk, 771; Alco- holic Fermentation of Milk, 771; Bitter Milk, 771; Colored Milk, 772; Adulterations of Milk. 772; Dirtv Milk— The Dirt Test, 772; Clarification, 773; Bacteria in " Milk, 774; The Germicidal Propertv of Milk, 776; Diseases Spread by Milk, 777: The Character of Milk-Borne Epidemics, 783; Dried Milk, 784; Fresh Milk Products, 785; Butter, 785; Inspection, 788; Pasteurization, 788; The Effect of Heat upon Milk, 792; The Essential Requirements for a Safe and Satisfactory Milk Supply, 793.
The Bacteriological Examination of Milk
Number of Bacteria, 794; Kinds of Bacteria, 796.
The Microscopic Examination of Milk
The Stewart-Slack Method. 797; The Doane-Buckley Method, 798; The Prescott-Breed Method, 798.
Chemical Analysis of Milk t
Total Solids, 798; Determination of Total Solids, 799; Deter- - mination of Fats, 800; Determination of Milk Sugar, 802; Deter- mination of Proteins, 804 ; Water, 805 ; Reaction, 806 ; Specific Gravity, 807; Field Tests, 808; Heated Milk, 808; Tests for Enzymes, and Their Significance, 808; Tests for the Adultera- tion of Milk, 810.
III. ANIMAL FOODS: MEAT, FISH, EGGS, ETC .814
Meat
Structure and Composition, 814; Nutritive Value, 815; Sources, 816; Recognition of Spoiled Meat, 817; Prevention, 818; Meat Preservatives, 818.
Meat Inspection
General Considerations, 818; The Abattoir, 820; Qualifications of a Meat Inspector, 822; The Freibank or Three-Class Meat System, 822; Emergency Slaughter, 823; Methods of Slaughter, 824; The United States jNIeat Inspection Law, 825; Ante- Mortem Inspection, 825; Post-Mortem Inspection, 826.
Animal Parasites
Trichinosis, 830; The Pork or Measly Tapeworm, 834; Taenia Saginata, 835; Echlnococcus Disease, 836.
XX CONTENTS
CHAPTER
Fish
Physiological Fish Poisoning, 837; Bacterial Poisons, 838; The Fish Tapeworm, 839.
Shellfish
General Considerations, 840; Oysters, 842: Mussel Poisoning, 843.
Bob-Veal 846
Eggs
Nutritive Value, 847; Classification, 848; Bacteria in Eggs, 849; Eggs and Disease, 849.
Plant Foods
Tubers, 851; Roots, 8.51; Fruits, 851; Carbohydrate Food Preparations, 851; How Plants May Injure Health, 851; The Nutritive Value of Plants, 850; Poisoning from Plant Foods, 856.
SECTION VI AIE
I. COMPOSITION OF THE AIR : 865
General Consideeations 865
Oxygen, 867: Nitrogen, 869; Argon, 869; Ozone, 869; Hydrogen Peroxid, 871; Ammonia, 872; Mineral Acids, 872; Carbon Dioxid, 872.
II. PRESSURE, TEMPERATURE, AND HUMIDITY 887
Peessuee
Normal Atmospheric Pressure, 887 ; Diminished Atmospheric Pressure, 887 ; Increased Atmospheric Pressure, 890.
Movements of the Atjiospheee 891
Tempebature of the Aib
General Considerations, 893; Methods of Recording Tempera- ture, 895.
Humidity
Aqueous Vapor, 896 ; Methods of Determining Humidity in the Air, 900; Relation of Humiditv and Temperature to Health, 904; The Kata-Thermometer, 907; "^Effects of Warm Moist Air, 910; Effects of Cold Damp Air, 911; Effects of ^Yarm Dry Air, 912.
III. MISCELLANEOUS 914.
Odobs 914
Light — Ocular Hygiene 916
Electricity 925
Radio-Activity 925
Smoke 926
Fog 929
Dust 929
IV. BACTERIA AND POISONOUS GASES IN THE AIR .... 936
Bacteria in the Aie
General Considerations, 936 ; Method for Determining Bacteria in the Air, 938; Air and Infection, 939.
CONTENTS xxi
rllAPTEII VAOt
Poisonous Gases in tiik Aik
Carbon Monoxid, 941; Illuiiiinatiiiy (Jas, 1)44; Utlier Gases in the Air, 94(5.
Sewer Gas
General Considerations. 949; Bacteria in Sewer Air, 9.10; Ac- cidents in Sewers, 951; Illustrative Cases of Deatli by Sewer Gas, 952; Prevention of Accidents in Sewers, 954; Ventilation of Sewers, 954.
V. FRESH AND VITIATED AIR 955
The Benefits of Fresh Air 955
The Effects of Vitiated Air
General Considerations, 955; The Effects of Increased Carbon Dioxid and Diminished Oxygen, 957; Poisons in tlic Expired Breath, 958; Physical Changes in the Air, 960; Reinspiration of Expired Air, '963.
Summary 964
VI. VENTILATION AND HEATING 966
Vextilatiox
General Considerations, 966; Air Washing, 968; Recirculation, 968 ; Vitiation by Respiration, 969 ; Vital Capacity of the Lungs, 969; Dead-space' Air, 970; Factor of Safety, 971; The Amount of Air Required, 971; Standards of Purity — Efficiency of Venti- lation. 973; The Size and Shape of the Room, 975; Inlets and Outlets. 977; External Ventilation, 979; Natural Ventilation, 979; Mechanical Ventilation, 984.
Heatin^g
General Considerations, 984; Open Fires, 986; Franklin Stoves, 986; Open Gas and Oil Heaters, 986; Hot-air Furnaces, 986; Hot-water and Steam Pipes, 987; Electric Heating, 988; The Cooling of Rooms, 988.
SECTION YII SOIL
L GENERAL CONSIDERATIONS 991
Classification of Soils, 992; Surface Configuration, 993; Com- position of the Soil. 993: Physical Properties, 994; Soil Air, 996: Soil Water, 996; The Nitrogen Cvcle, 998: The Carbon Cycle, 1002.
II. SOIL AND ITS RELATION TO DISEASE 1003
Bacteria in Soil, 1003; Pollution of the Soil. 1004; Dirt, 1005; Cleanliness, 1006; Influence of Soil upon Health, 1007; Diseases Associated with Soil, 1007.
SECTION YIII WATEK
GENERAL CONSIDERATIONS 1015
Composition, 1015; Classification. 1016; Properties, 1017; Uses in the Body, 1017;. Amount Used and Wasted, lOlS; Dual Water Supply, 1021.
xxii CONTENTS
SOUECES OF WATEK
Eain Water, 1022; Surface Waters, 1020; Ground Water, 1032.
SOUKCES AND NaTUKE OF WaTEE PoLLUTLON AND INFECTION
General Considerations, 10-13; Simple Tests to Determine Sources of Pollution, 1043; Interstate Pollution of Streams. 1044: Pollu- tion of International Boundary Waters, 1045; The Care of Catch- ment Areas, 104G.
II. SANITARY ANALYSIS OF WATER 1048
Standard Methods . .' 1048
Odoks and Taste
General Considerations, 1050; Method of Determining Odor, 1051; Prevention and Removal of Tastes and Odors, 1054.
COLOB
General Considerations, 1055 ; Method for Estimating Color, 1056; Platinum-Cobalt Standard, 1056.
Tuebidity
General Considerations, 1057; Methods for Estimating Turbidity, 1058.
Reaction" 1059
Total Solids ^ 1060
Haedness
General Considerations, 1061; Methods, 1063.
Oeganic Matter
Free Ammonia, 1066; Albuminoid Ammonia, 1069; Nitrites, 1071; Nitrates, 1072.
Chlorids 1074
Chlorin , 1075
Oxygen
Oxygen Consumed, 1077 ; Dissolved Oxygen, 1079. Iron
General Considerations, 1080; Iron Pipes, 1081. Lead
Tests, 1082.
III. MICROSCOPICAL EXAMINATION OF WATER 1084
The Sedgwick-Rafter Method, 1084; Significance of Ihe Examina- tion, 1086.
Bacteriological Examination
The Number of Bacteria in Water, 1087 ; Method for Determin- ing the Number of Bacteria in Water, 1089; Kinds of Bacteria in Water, 1090.
IV. INTERPRETATION OF SANITARY WATER ANALYSIS . . . lOHG
General Considerations 1096
Allowable Limits, 1097 ; Illustrative Analyses Interpreted, 1099.
V. THE PURIFICATION OF WATER . . . 1108
Nature's Methods of Purifying Water
General Considerations, -1108; Evaporation and Condensation, 1109; Self-purification of Streams, 1109; Storage in Lakes and Ponds, 1111.
CONTENTS xxiii
CHAPTEU PAGE
Distilled Water 1112
Boiled Water 1112
Filters
Slow Rand Filters, 1113; INk'oIianieal Filtora. 1122; Household Filters. 1127; Scrubbing or Roughing Filters, 1128; Screening, 112S.
Storage ■ 1128
Sedimentation 1129
Chemical ]\Ietiiods of Purifying Water
Ozone, 1129; Clilorinated Lime — Bleaciiing Powder or "Ciilorid of Lime," 1132; Chlorin, 1131); Permanganate of Potash, 1140; Alum or Sulphate of Aluminium, 1141; Sulphate of Iron and Lime, 1142: Metallic Iron: The Anderson Process, 1143; Cop- per Sulphate, 1143.
Ultraviolet Rats 1144
VI. WATER AND ITS RELATION TO DISEASE 1147
General Considerations 1147
The Mills-Reincke Phenomenon 1148
Non-Specific Diseases Due to Water
General Considerations, 1149; Goiter, 1150; Lead Poisoning, 1155.
Specific Diseases Due to Water
General Considerations, 1159; Cholera. 1161; Typhoid Fever, 1167; Dysentery, 1179; Diarrhea. 1180; Animal Parasites, 1181.
Sanitation of Swimming Pools 1182
Drinking Fountain 1184
Ice
General Considerations, 1184; Natural Ice, 1186; Manufactured Ice, 1187; Ice and Disease, 1188.
SECTION IX
SEWAGE DISPOSAL By George C. Whipple
General Considerations 1191
Importance of Speedy Removal of Fecal Matter, 1191; Dry Earth System, 1192; Water Carriage System, 1192; Separate and Combined Systems, 1193; Quantity of Sewage, 1194; Com- position of Sewage, 1194; Ventilation and Flushing of Sewers, 1196.
Stream Pollution
Sewage Disposal by Dilution, 1196; Hygienic Aspects of Stream Pollution, 1198; Protection against Pollution, 1199; Funda- mental Principles of Sewage Treatment. 1200: Preparatory Processes. 1200; Purification Processes. 1204: Finishing Proc- esses, 1209; Choice of Methods, 1209; Relative Bacterial Effi- ciency of Different Processes, 1210; Management of Sewage Treatment Works, 1211; Treatment Plants as Nuisances, 1211; Nuisances Caused by Trade Wastes, 1212.
Cooperative Sanitation 1212
The Rural Problem of Sewage Disposal 1213
xxiv CONTENTS
SECTION X
EEFUSE DISPOSAL - By George C. Whipple
PAGK
Genebal Considerations 1219
Incineration Plants, 1221; Reduction Plants, 1223; Feeding Garbage to Hogs, 1224; Collection of Garbage, 1224.
SECTION XI
VITAL STATISTICS By John W. Trask
General Considerations 1225
Vital Statistics
Definition, 1227; Development, 1227; Based upon Population, 1228.
Population Statistics
Source of Data, 1228; Nature of Census Information, 1229; Sources of Error in Census Enumerations, 1229 ; Fluctuation in Population, 1230; Estimates of Population, 1230.
Marriage Statistics
Marriage Rates, 1234; Factors Influencing Marriage Rates, 1234; Uses of Marriage Registration, 1234.
Birth Statistics
Registration in the United States, 1235; Birth Rates, 1238; Sources of Error in Birth Statistics, 1239 ; Uses of Birth Regis- tration and Statistics, 1240; Factors Influencing Birth Rates, 1241.
Morbidity Statistics
General Considerations, 1242; Morbidity Statistics in the United States, 1243; The Model Law for Morbidity Reports, 1245; Re- sults of Notification in Certain States and Cities, 1246 ; Source of Statistical Data, 1247 ; Nature of Information Secured by Morbidity Notification, 1251; Standard Notification Blank, 1251; Sources of Error in Morbidity Statistics, 1252; Uses of Mor- bidity Reports and Statistics, 1253; Morbidity Rates, 1254; Hospital Statistics and Sickness Insurance Records, 1255 ; Fac- tors Influencing Morbidity Rates, 1255 ; Notification of Occupa- tional Diseases, 1255; Morbidity Statistics of Military Popula- tions, 1257.
Mortality Statistics
General Considerations, 1259; Registration of Deaths in the United States, 1260; United States Registration Area for Deaths, 1260; Source of Data, 1261; The Standard Death Certificate, 1262; Sources of Error, 1262; Uses of Death Registration, 1266 ; Death Rates, 1267; Factors Affecting Death Rates, 1270; Inter- national List of Causes of Death, 1272.
Infant Mortality 1275
Life Tables 1276
SECTION XII
INDUSTEIAL HYGIENE AND DISEASES OF OCCUPATION General Considerations 1279
Some Fundamental Considerations in Prevention
General Considerations, 1283; Hours of Work, 1284; Fatigue, 1284; Minors, 1286; Women, 1287; Factory Inspection, 1289; Preventable Accidents, 1290; Sedentary Occupations, 1291.
CONTENTS XXV
CHAPTER PAGE
Diseases of Occupation
Glassifk-ution of llie Oiriipatioiial Disoaaes, 121>2; Lead, 1203; Phosplioriis, i;{();}; Arsoiiic, l.Jd."); Mercury, i:U)7; Carbon Monoxid, l.SOH; llydroj^'cn Snlphid, i:{<)!): Other Industrial Poisons, l.UO; Dustv Trades, l;{i;{; Tlie Textile industries, ^•^\^)■. Wood Dust. 1319; Mininfr, l;n!»; Effects of Heat, 1321; Com- municable Infections, 1322; Caisson Disease, 1324.
SECTION Xlll SCHOOL SANITATION AND PERSONAL HYGIENE
General Considekations 1325
Healtli Education. 1328; School Building, 1328; Tiie School- room, 1329; The School Furniture, 1330; Posture, 1334; Recess, 1334; Lighting, 1335; Ventilation and Heating, 1336; Open Air Schools, 1337; Water-closets and Urinals, 1337; Cleanliness, 1338; Medical Inspection, 1338; The Communicable Diseases of Childhood, 1341; Closing Schools on Account of Epidemics, 1342; The Eyes, 1342; The Ears, 1343; Oral Prophylaxis, 1343; Nose and Throat, 1346; Diseases of the Skin, 1347; Nervous Diseases and Mental Defects, 1348; Chorea, 1348; Vaccination, 1350.
SECTION XIV DISINFECTION
I. GENERAL CONSIDERATIONS 1351
Disinfection, 1351; Nature's Disinfecting Agencies, 1353; Cleanli- ness, 1353; Antibiosis and Symbiosis, 1354; When and Where to Disinfect, 1355; Qualifications of the Disinfector, 1355; Con- trols, 1356; Disinfection Must Be in Excess of Requirements, 1356; Specificity of Germicides, 1356; Chemotherapy, 1357; The Ideal Disinfectant, 1357; Concurrent Disinfection, 1357; Ter- minal Disinfection, 1357; Penetration, 1358; Organic Matter, 1359; Time, 1359; Speed of Disinfection and Stability of Dis- infectants, 1360; Temperature, 1360; Emulsions and Solutions, 1361; Dilution, 1362; Reaction, 1362; The Mechanism of Bactericidal Action, 1362; The Choice of Germicide, 1364.
The Staxdakdization of Disixfectaxts
, General Considerations, 1364; Methods, 1365; Carbolic Coeffi- cient, 1366.
II. PHYSICAL AGENTS OF DISINFECTION 1375
Sunlight, 1375; Ultraviolet Rays, 1375; Electricity, 1377; Pres- • sure, 1377; Burning, 1377; Dry Heat, 1378; I3oiling, 1378; Steam, 1379.
III. CHEMICAL AGENTS OF DISINFECTION 1390
Gaseous Disinfectants — Fumigation
Preparation of the Room, 1390; Formaldehyd Gas, 1391; Sul- phur Dioxid, 1396; Hydrocyanic Acid Gas, 1402; Chlorin, 1403; Oxygen, 1404; Ozone, 1404.
Liquid Disinfectants
General Considerations, 1404; Methods of Using Chemical Solu- tions, 1405; Metallic Salts, 1406; Bichlorid of Mercury, 1406; Silver Salts, 1407; Zinc Salts, 1408; Ferrous Sulphate, 1408; Sulphate of Copper, 1408; Coal Tar Creosote, 1408; Carbolic Acid, 1409; Phenol, 1410; The Cresols, 1411; Liquor Cresolis Compositus. 1412; Lvsol, 1412; Creolin, 1412; Aseptol, 1412; Asaprol, 1413; Sanatol, 1413; Solveol and Solutol, 1413; Naph-
xxvi CONTENTS
CHAPTER PAGE
thols, 1413; Ambrine, 1413; Naphthalene, 1413; Formalin, 1414; Potassium Permanganate, 1415; Hydrogen Peroxid and Other Peroxids, 1415; Lime, 1416; Bromin and lodin, 1417; Anti- formin, 1421; Dyestuffs, 1422; Acids, 1422; Alcohol, 1423; Soaps, 142'4.
Convenient Formula fob Disinfecting Solutions
Bichlorid of Mercury — Corrosive Sublimate, 1425; Formalin, 1425; Milk of Lime, 1426; Carbolic Acid, 1426; Chlorinated Lime, 1426.
IV. METHODS OF DISINFECTIOIST 1439
Air, 1427; Stables, 1428; Railroad Cars, 1430; Feces, 14.32; Sputum, 1434; Bed and Body Linen, 1435; Books, 1435; Cadavers, 1436; Thermometers, 1437; Wells and Cisterns, 1437.
SECTION XV MILITAKY HYGIENE
Genebal Considebations
Comparative Loss in Campaign from Sickness and Wounds, 1441.
Recbuits and Recbuiting
General Considerations, 1442; The Physical Examination, 1444; Age, 1444; Character and Mental Condition, 1445; Height, Weight and Chest Measurements, 1446; Vision, 1447; Teeth, 1448; Vaccination, 1448; General, 1448; Training, 1449,
Duties of the Medical Offices 1450
Equipment .
General Considerations, 1451'; The First-aid Packet, 1453; Clothing, 1454.
Diseases of the Soldier
General Considerations, 1458; War Gases, 1459.
Sanitation in Camp and on the March
Personal Hygiene of the Soldier, 1459; The March, 1459; Forced Marches, 1461; Discipline and Sanitation, 1462; Sani- tary Police, 1463; Transportation, 1464.
Camp Sites
General Considerations, 1465; Topography, 1465; Tentage,
1467; Care of Tents, 1468. Sanitation of Babbacks and Camps
General Considerations, 1469; Water, 1470; Disposal of Excreta,
1473; Disposal of Garbage, 1475.
Sanitation of Teenches 1478
Hygiene in the Tropics 1479
Cold Climates 1481
SECTION XVI
A LABORATOEY COURSE IN PREVENTIVE MEDICINE AND HYGIENE
Schedule 1483
Vaccination, 1484; Standardization of Disinfectants, 1485; Water, 1486; Milk, 1489; Bacterial Vaccine, 1492; Vital Statistics, 1493; Diphtheria Diagnosis, 1496; Classification of Pneumococci, 1498; Meningococcus Isolation and Carrier Detec- tion, 1499; Sanitary Survey of a City or Town, 1501.
Index l^Oo
LIST OF ILLUSTRATIONS
FicrKB
PAGE
1. Vaccination scars 10
2. The course of the eruption 13
3. Vaccinia: course of the eruption 14
4. Vaccinia: course of the eruption (continued) 15
5. Course of vaccination and revaccination 19
6. Smallpox mortality per 100,000 population in Breslau ... 32
7. Smallpox mortality per 100,000 population in Vienna ... 33
8. Smallpox mortality per 100,000 population in Prussia ... 36
9. Smallpox mortality per 100,000 population in Austria ... 37
10. Chart showing relation of enforcement of muzzling law to
prevalence of rabies in Great Britain 43
11. Influence of public water supplies on the typhoid fever death
rate 119
12. Immediate and striking effect of purifying a badly infected
water supply upon the typhoid situation 121
13. Abrupt reduction in death rates from typhoid fever incident to
water purification in four American cities 122
14. Hookworms, natural size 155
15. Hookworm embryo 155
16. Chart showing the decline in the death rate from tuberculosis . 182
17. Curve of the influenza epidemic in the naval training camp at
Pelham Park, New York, September and October, 1918 . 243
18. "West swab tube 256
19. Diagram illustrating the method of taking material from the
nasopharynx by means of a special swab 256
20. A South African blood-sucking fly (Pangonia), illustrating
long proboscis to pierce heavy fur of certain animals . . . 261
21. Example of sealing door for purpose of fumigation .... 267
22. Anopheles punctipennis 288
23. Stegomyia calopus (female) 297
24. Head of Stegomyia calopus (male) 298
25. Eggs of Stegomyia calopus 299
26. Larva of Stegomyia calopus, Eespiratory siphon of culex to
the right 300
27. Pupa of Stegomyia calopus 301
28. House fly showing proboscis in the act of eating sugar . . . 307
29. Eggs of house fly as laid in a mass 308
'30, Eggs of house fly 308
31. Larvae of house fly 309
xxvii
xxviii LIST OF ILLUSTRATIONS
FIGURE pj^ej.
32. Puparium of house fly .- 309
33. Stable fly 310
34. Head showing proboscis 310
35. Wing of stable fly 311
36. The "little house fly" 312
37. Wing of house fly, showing how it carries dust particles . . 313
38. The Hodge fly trap on a garbage can 315
39. Tsetse fly 318
40. The Indian rat flea 323
41. The common rat flea of Europe and North America . . . 324
42. The human flea 324
43. A squirrel flea 327
44. A general scheme for testing plague rat infection, city of Manila 352
45. Isolated plague-infested center, Manila, P. 1 353
46. The Texas fever tick 357
47. Rocky Mountain spotted fever tick 358
48. Serbian barrel 367
49. Delousing plant 371
50. The bedbug , .... 379
51. Diagrammatic representation of complement fixation . . . 400
52. The cell with its various combining groups or side chains known
as receptors 549
53. The toxin molecule: showing the haptophore (combining) group,
and the toxophore (poison) group 549
54. The first stage of antitoxin formation: a toxin molecule an-
chored to a receptor 549
65. The second stage: continued stimulation causes a reproduction
of receptors 550
56. Third stage: The receptors beginning to leave the cell . . . 550
57. Fourth stage: the receptors have left the cell and float free in
the blood — antitoxin 551
58. The neutralization of a toxin by antitoxin; the free receptors
in the blood have united with the toxin — antitoxic immunity 551
59. Showing complement and immune body 551
60. Showing an immune body having two affinities 552
61. Diagram illustrating deviation of complement 584
62. History of the family Zero 616
63. History (condensed and incomplete) of three markedly able
families 6l8
64. Wilson's theory of inheritance modified by Lock 623
65. Diagram showing the course of color heredity in the Andalusian
fowl, in which one color does not completely dominate another 626
66. Diagram showing the course of color heredity in the guinea-pig
in which one color (black) completely dominates another
(white) 626
67. Model to illustrate the law of probability or chance .... 632
LIST OF ILLUSTllATIONS xxix
FIQl'RR ■ PA«r.
68. Normal curve . . .- . . . 633
69. Curve made up of variates 636
70. Family history showing deaf-mutism 649
71. Family history showingr polydactylism 652
72. Family history showing Huntington's chorea 656
73. Family history showing feeble-mindedness 657
74. Sections through seeds of rice, wheat and corn 681
75. Curve showing thermal death point of Bacillus botulinus . 712
76. Curve showing rate of destruction of botulinus toxin . . . 714
77. Unsanitary surroundings of a cowbarn 765
78. Conditions under which it is difficult to cleanse and disinfect
milk bottles and milk pails 773
79. A dark, poorly ventilated cow shed, difficult to keep clean . . 775
80. Automatic temperature recorder for pasteurizers 790
81. Strauss home pasteurizer 792
82. Trichinella spiralis. Entire life cycle in each host .... 831
83. Taenia solium, the pork or measly tapeworm 834
84. Beef tapeworm 836
85. Dibothriocephalus latus, the fish tapeworm 839
86. Portable Haldane apparatus for small percentages of carbon
dioxid 879
87. Petterson-Palmquist apparatus 881
88. Wolpert air tester . . 884
89. Fitz air tester 885
90. Diagram showing absolute humidity in grains at different tem-
peratures 897
91. Sling psychrometer 901
92. Eelative humidity table 902
93. Dew-point apparatus 903
94. The Kata-thermometer 908
95. Table showing the density of smoke, in accordance with the
Eingelmann chart, which may be emitted from the various classes of stacks in Boston, Mass., and duration of such
emission 928
96. Palmer water-spray apparatus for the collection of aerial dust . 934
97. Magnus aspirator 938
98. The double aspirator 938
99. The position of inlets and outlets and their relation to the air
currents in a room 978
100. "Window ventilator 979
101. Diagrammatic sketch of various provisions for ventilation . 980
102. Fairfield system of window ventilation 983
103. The nitrogen cycle 999
104. The nitrogen cycle in diagrammatic vertical section .... 1000
105. Ground water 1032
xxx LIST OF ILLUSTKATIONS
KlfitB!! . PAGE
106. Usual method of pollution and even infection of- wells . . . 1037
107. Proper construction of a well 1038
108. Popular idea of how wells become infected from surface
pollution * 1039
109. Depression of the ground water level by pumping and tendency
to draw near-by pollution from the soil or cesspool . . . 1040
110. In a limestone formation it is difficult to tell anything about
the source of water obtained from a well 1041
111. Algae commonly found in water 1052
112. Algae commonly found in water (continued) 1053
113. Oil droplets in a diatom 1054
114. Graduated cylindrical funnel and concentrating attachment
used in the Sedgwick-Rafter method 1085
115. Diagram illustrating the character of the ground water in rela-
tion to soil pollution, to assist in the interpretation of a
sanitary analysis * . 1098
116.' Diagram showing location of samples 1106
117. Section of an English filter bed 1114
118. The arrangement of a slow sand filter 1115
119. Diagram illustrating "loss of head" 1118
120. An ozonizer 1130
121. An installation for treating water with ozone ....... 1131
122. Asiatic cholera and the Broad Street pump 1163
123. Asiatic cholera and the Broad Street well . 1164
124. Water supply of Hamburg . 1166
125. Change in water supply 1169
126. Mean death rates from typhoid fever, 1902-1906, in 66 American
cities and 7 foreign cities 1170
127. Map of Plymouth, Penn., in 1885 1173
128. Map showing water supply of Ashland, Wisconsin .... 1175
129. Inclined screen operated by water wheel 1201
130. Reinsch-Wurl screen . 1202
131. Cross section of septic tank 1202
132. Typical section of an Imhoff tank 1203
133. Chemical precipitation plant at Worcester, Mass., outlet . . 1204
134. Triple contact beds at Hampton, England 1205
135. Cross section of intermittent sand filter 1206
136. Cross section of contact bed . . 1206
137. Typical section of sprinkling filter 1207
138. Trickling filter at Birmingham, England . 1208
139. Septic tank and chemical precipitation tanks at Rochdale,
England 1209
140. Intermittent sand filtration bed at Brockton, Mass 1214
141. Filter bed with sand ridged for winter operation at Brockton,
Mass 1215
LIST OF ILLUSTRATIONS xxxi
KUn 1!E PAGE
142. Discharge of sewage upon a filter bed at Brockton, Mass, . .1216
143. Digestion process of garbage reduction 1220
144. A simple type of garbage incinerator 1222
145. Cobwell process of garbage reduction, New Bedford, Mass. . 1223
146. Births (including stillbirths), persons married, and deaths
(excluding stillbirths) registered per 1,000 population per annum, Michigan, 1871-1915 1238
147. Diphtheria — number of cases notified per annum for each death
registered in Michigan, 1884-1912 1247
148. Smallpox — number of cases notified per annum in Michigan,
1883-1915 1248
149. Smallpox — number of cases notified per annum for each death
registered, Michigan, 1883-1915 1248
150. Scarlet fever — number of cases notified per annum for each
death registered, Michigan, 1884-1915 1249
151. Measles — number of cases notified per annum for each death
registered, Michigan, 1890-1917 1249
152. Births and deaths (exclusive of stillbirths) per 1,000 population
per annum registered in Mass., 1871-1911 1266
153. State statistics of original registration 1276
154. System of hoods and ventilators to carry off the fumes from
the furnaces in a foundry 1281
155. Red oxid of lead and litharge being mixed in the manufacture
of storage batteries 1295
156. A worker with lead oxid, showing respirator to protect himself
against the poisonous dust 1298
157. Workmen exposed to zinc fumes in brass casting, causing a con-
dition known as "brass-founders' ague" 1312
158. An effective dust-removing system in the boot-and-shoe in-
dustry. Edge trimming 1315
159. A very dusty trade — drum with nails which combs out the
small pieces of broom corn 1316
160. The stone industry . . . ^ 1820
161. Faulty posture . . . . ' 1332
162. The Heusinger desk 1333
163. Boston school desk and chair 1334
164. Device for determining carbolic coeflScients 1368
165. Arrangement of tubes in water-bath and their contents . . . 1370
166. Section through Arnold steam sterilizer 1381
167. Section through autoclave 1382
168. Bramhall-Deane steam sterilizer 1382
169. Cross section through steam disinfecting chamber .... 1383
170. Longitudinal section through steam disinfecting chamber . . 1384
171. Kinyoun-Francis steam disinfecting chamber 1385
172. Automatic thermometer 1387
173. Plan showing the method of installing the double-ended steam
chamber at a national quarantine station 1388
xxxii LIST OF ILLUSTRATIONS
FIGUBE PAGE
174. Flaring- top tin bucket for generating formaldeliyd by the per-
manganate method 1394
175. The pot method of burning sulphur 1398
176. Large stack burner for sulphur, with 15 of the 18 pans removed
to show construction 1399
177. Liquefied sulphur dioxid in tin can 1400
178. Section through double sulphur furnace 1402
179. Steam sterilizer for bedpans 1434
180. Proper and improper methods of distributing the equipment . 1452
181. The normal foot 1457
182. Shape of the U. S. military shoe 1457
183. Camp of a regiment of infantry, war strength 1466
184. Ishiji filter (Japanese model) 1470
185. Darnall siphon filter 1471
186. Construction of pit latrine 1473
187. Straddle-pit cover ! . . . 1474
188. Pit crematory 1474
189. Pit for kitchen refuse 1475
190. Urine soakage pit 1476
191. A rock pile crematory 1477
192. U. S. Army grease trap 1477
193. Improvised ice-box 1479
194. Water bag to cool water in hot countries 1480
PREVENTIVE MEDICINE AND HYGIENE
SECTION I PREVENTION OF THE COMMUNICABLE DISEASES
CHAPTER I
DISEASES HAVING SPECIFIC OR SPECIAL PROPHYLACTIC
MEASURES
SMALLPOX AND VACCINATION
The prevention of smallpox depends primarily upon vaccination, sec- ondarily upon isolation and disinfection. Vaccination was the first specific prophylactic measure given to man ; it produces an active im- munity to smallpox. On account of its importance and great practical value this subject will be considered in some detail, for much of the antivaccination sentiment is due to ignorance or misconstruction of the facts.
Smallpox was once the most prevalent and dreaded disease in the world. Before the days of vaccination only five persons out of a hundred escaped it, and about a quarter of those who took it died. Many of those who recovered were mutilated or maimed for life.
Historical Note. — The credit of giving vaccination to the world is due to Jenner, who proved through carefully planned experiments that cowpox protects against smallpox. This fact had been familiar to the farmers and folk of England as a vague tradition for a long time. A young girl who sought medical advice of Jenner, when a student at Sudbury, said, "I cannot take smallpox because I have had cowpox" ; this remark made a strong impression upon the young medical student.
Benjamin Jesty, a Dorchestershire farmer, in 177-i successfully vac- cinated his wife and two sons. Plett, in Holstein, in 1791 also success- fully vaccinated three children. It was Jenner, however, who through logical and scientific methods proved that a person who has had the mild disease, cowpox, enjoys protection against the serious and often
1
2 DISEASES HAVING SPECIAL PROPHYLAXIS
fatal disease, smallpox. Waterhouse and others soon repeated and cor- roborated Jenner^s experiments and helped to establish the soundness of his conclusions.
Jenner made his crucial experiments in 179G, when he transferred the vaccine matter from the hand of a dairy maid (Sarah Nelms) to the arm of James Phipps, a boy about 8 years old. Sarah jSTelms scratched her hand with a thorn and "was infected with the cowpox from her master's cows, in May, 1796." Jenner transferred the vaccine virus from the eruption upon the hand of Sarah Nelms to the arm of James Phipps on May 14, 1796. A typical take followed. "In order to ascertain whether the boy, after feeling so slight an affection of the system from the cowpox virus, was secure from the contagion of the smallpox, he was inoculated the first of July following with variolous matter, immediately taken from a pustule. Several slight punctures and incisions were made on both arms, and the matter was carefully in- serted, but no disease followed. The same appearances were observable on the arm as we commonly see when a patient has had variolous mat- ter applied, after having either the cowpox or the smallpox.^ Several months afterward he was again inoculated with variolous matter, but no sensible effect was produced on the constitution."
In addition to such direct experimental proof, Jenner inoculated smallpox matter into ten persons who had at some previous time con- tracted cowpox.
Date of Inoculation with Smallpox
1. 1778
2. 1791
3. 1792
9. 10.
1795
6.-)
7. [■ 1797
8. J
After 1782 Not stated
Name
Mrs. H.
Mary Barge Sarah Portlock r Joseph Merret I William Smith Elizabeth Wynne Sarah Wynne William Rodway Simon Nichols John Phillips
Ascertained to have had Cowpox
When very young 31 years previously 27 years previously 25 years previously 1, 5, 15 years previously 10 months previously 9 months previously 38 years previously Some years previously 53 years previously
In justification of such human experimentation it should be re- membered that at that time the inoculation of smallpox matter into healthy individuals was an acknowledged method of preventing that disease. Jenner himself was inoculated when a boy. The question of "inoculation" (with smallpox) as contrasted with "vaccination" (with cowpox) will be discussed presently.
With such proof as this Jenner put a popular belief upon a scien- tific basis. He demonstrated that cowpox is a local and mild disease
* This keen observation shows that Jenner was familiar with the modified take, recently rediscovered and now known as the immediate reaction.
SMALLPOX AND VACCINATION 3
in man, that it may be readily transferred from man to man, and that it protects against smallpox. The chain of evidence was complete, but he first proved his thesis to his own satisfaction before he gave it to the world. He said himself: "I placed it on a rock where I knew it would be immovable Ijeforc I invited the public to take a look at it." Jenner presented the results of his observations to the Royal Society, of which he was a Fellow, but the paper was refused. He then published it in 1798 as a book, modestly entitled, "An Inquiry Into the Causes and Eifects of the Yariolae Vaccinae, a Disease Discovered in Some of the Western Counties of England, Particularly Gloucestershire, and Known by the Name of the Cowpox." Every student of preventive medicine should read this brief "inquiry'' in the original. It may be taken as a model of careful observation and logical presentation, showing great self-restraint and moderation of an observant, imaginative, and judicial mind.
Dr. Benjamin Waterhouse, the first professor of Theory and Prac- tice of Physic in the Harvard Medical School, early became convinced of the value of Jenner's demonstration and obtained some vaccine virus on threads from abroad. On July 8, 1800, he vaccinated his son, Daniel Oliver Waterhouse, then five years old. This was the first person vac- cinated in America, so far as existing records show. After successful vaccination with cowpox his two sons and other members of his house- hold were inoculated with smallpox at the Smallpox Hospital by Dr. Zabdiel Boylston, with negative results.
In Boston on August 16, 1802, nineteen boys were vaccinated with the cowpox. On November 9th twelve of them were inoculated with smallpox; nothing followed. A control experiment was made by inocu- lating two unvaccinated boys with the same smallpox virus; both took the disease. The nineteen children of August 16th were again unsuc- cessfully inoculated with fresh virus from these two boys. This is one of the most crucial experiments in the history of vaccination, and fully justified the conclusion of the Board of Health — "cowpox is a complete security against the smallpox."
Thomas Jefferson helped materially to spread the new doctrine in this country, and, in 1806, in writing to Jenner, said : "Future nations will know by history only that the loathsome smallpox has existed and by you has been extirpated.'" This prophecy has by no means been ful- filled— though eminently possible.
YACCINATION
Vaccination may be defined as the transference of the virus from the skin eruption of an animal having vaccinia or cowpox into the skin of another animal. Vaccination, then, consists in introducing the active
4 DISEASES HAVING SPECIAL PEOPHYLAXIS
principle of cowpox into the skin of a susceptible animal. For over one hundred years vaccination (from vacca — a cow) was a specific term limited to the introduction of the virus of cowpox into the skin, in order to induce vaccinia and prevent variola. In recent years, however, the term has been used in a generic sense to include the introduction of many different substances in many different ways and for many different purposes. Thus we speak of attenuated or killed bacterial cultures as bacterial vaccines; and the subcutaneous inoculation of organic sub- stances of diverse origin and nature is often spoken of as vaccination. We hear of typhoid vaccines, anthrax vaccines, staphylococcus vaccines, and we read in the literature of animals "vaccinated" with extracts of cancer and other organic substances. For distinction between a vaccine and a virus, see page 534.
VACCINE VIEUS
^, Vaccine virus is the living specific principle in the matter obtained from the skin eruption of animals having a disease known as "vaccinia" or "cowpox." A^accine virus is obtained from calves, but may also be obtained from older cattle, from man, rabbits, buffalo, camels, and other mammals.
Cowpox, or vaccinia, is an acute specific disease to which many animals are susceptible, namely, man, cattle, camels, rabbits, monkeys, guinea-pigs, rats, etc. The disease runs practically the same clinical course in all susceptible species. The eruption is always local and confined to the site of the vaccinated area ; the constitutional symptoms are always benign and usually slight. Vaccinia or cowpox is a benign disease; when uncomplicated, it has never been known to cause death or leave any unpleasant sequelae.
After an incubation period of from three to four days the local eruption begins as a papule which soon develops into a vesicle, and later into an umbilicated pustule. Surrounding the vesicle is a red- dened, inflamed, and tender areola. The neighboring lymph glands are swollen and tender, and there may be slight fever lasting several days. The pustule dries, leaving a crust or scab, which comes away,- dis- closing a typical foveated or pitted scar.
Human and Bovine Vaccine Virus. — Vaccine virus is usually ob- tained from (1) bovine or (2) human sources.
Human virus is now seldom used, for the reason that the supply would not be sufficient. Upon the appearance of a smallpox outbreak it is sometimes necessary to have enough virus to vaccinate one hundred thousand or more people. Such large quantities evidently could not be obtained from man at any desired time. Another objection to the use of human virus is the possibility of transmitting syphilis, and perhaps
SMALLPOX AND VACCTNATIOX 5
other dit^oasos peculiar to iiiaii. It i^ not always jjractical to select donors so as to avoid such transmission.
When human seed is used the virus may be transferred directly from arm to arm; or the virus may be preserved dry in the scab; or the con- tents of the vesicle may be kept in either a dried or moist state, as de- scribed below for bovine virus. Arm-to-arm vaccination is still practiced in several parts of the world, particularly in Mexico, where it is claimed that it has the advantage of producing a better take; that the results are surer in that there are fewer unsuccessful vaccinations; and, finally, it is stated that the human virus affords a better immunity, but as to this there is no proof and some doubt.
Bovine virus has been used more or less since the time of Jenner, but especially since 1866 when the Beaugency strain was discovered, and more since 1891 when Copeman showed how to purify it with glycerin. It has the great advantage of being readily obtained in any amount and when desired. It may be purified, and it further totally eliminates the danger of conveying syphilis and other diseases peculiar to man.
Forms of Vaccine Vims. — Vaccine virus may be used in one of three forms: (1) fresh, (2) dry, (3) glycerinated.
The fresh virus may be taken from the eruption of the calf or man and transferred directly. Thus the Institut Tacc-inale at Paris still prefers to use the fresh virus. The vesicle is squeezed at its base be- tween the blades of forceps, and some of the content is transferred from the calf directly to the skin of the arm by means of a thumb lancet or any similar instrument.
The vaccinal matter may be dried, and the virus remains potent in this state a very long time, especially if kept cold and protected from light. The virus may be dried upon a splinter of ivory, bone, or other substance. Formerly physicians preserved the dried crust from a typical take. When needed, small portions of this crust were ground, moistened, and inserted into the skin.
Glycerinated virus consists of vaccine pulp treated with 50 per cent, glycerin. This purifies it and hence is preferable.
Vaccine Pulp and Vaccine Lymph. — A distinction is drawn between the pulp and the hinph. The pulp consists of the entire vesicle with its contents, which is scraped from the skin, and is composed of epi- thelium, leukocytes, bacteria, products of inflammatory reaction, the fluid content of the vesicle, debris, etc. The lymph is the serous fluid contained in the vesicle or which often exudes from the broken vesicle. When the eruption is produced on the skin of a calf in a large con- fluent area, the surface of the eruption is scraped away and the exuding "lymph" is placed upon points by dipping or brushing.
!Most of the active principle of vaccine virus is contained in the epi- thelial cells, and this portion is largely lost when only the lymph is
6 DISEASES HAVING SPECIAL PROPHYLAXIS
used. The pulp, which includes the lymph, therefore contains the virus in greater concentration, and is almost exclusively used in this country at the present time.
Dry Points versus Glycerinated Vaccine Vims. — The old-fashioned dry points were prepared by applying the vaccine lymph to splinters of ivory. Bone or glass were later substituted for ivory. Bone is un- desirable because it is difficult to sterilize and may contain tetanus spores. The only advantage of the dry point is its convenience in vaccinating. One disadvantage is that the virus dried upon such points cannot easily be purified as is the case with glycerinated pulp. Further, the points are used as scarifiers and the method of scarification favors irritation and infection of the wound. Dry points practically always contain more bacteria than the glycerinated virus. For these reasons points are no longer permitted in interstate traffic in accordance with the federal regulations.
The best container for single doses of vaccine virus is a capillary tube. These are easily sterilized, filled and hermetically sealed. They should be wiped with alcohol and broken with sterile gauze, and the contents can then safely be emptied by means of a small rubber bulb. "When many vaccinations are to be done, it is preferable to have the virus in bulk.
The Process of Ripening or Aging. — When the vaccine virus is fresh it is said to be "green." Glycerin is added to the green pulp, and after it has acted a certain period of time the virus is said to be "aged" or "ripe." The use of glycerin for this purpose was introduced by ]\Ioncton Cope- man ^ in 1891 for the purpose of preserving ^ and purifying the virus. The glycerin acts as a differential germicide, that is, it is comparatively harmless to the active principle in the vaccine virus, but destroys the frail non-spore-bearing bacteria. In time the virus itself succumbs. Vaccine virus must, therefore, not be used while green nor when too old. Manufacturers date their products as "not reliable after" 2 months in the summer time, and 3 months during the cold season.
Fifty per. cent, glycerin of the best quality is used. I have shown that no growth of bacteria, yeasts, or molds takes place in 60 per cent.* glycerin. Two to four parts of 50 per cent, glycerin are added to 1 part of the pulp by weight. The mixture is then thoroughly ground with a mortar and pestle by hand, or between glass rollers in a special mill driven by machinery. The pulp should be thoroughly broken up and a uniform suspension obtained. The amount of glycerin added depends upon the consistency and character of the pulp. The only objection
'Transactions of the International Congress of Hygiene, 1891. ^Glycerin also serves as a preservative for other " filterable viruses, as foot- and-mouth disease, infantile paralvsis, rabies, etc.
^Hyg. Lab. Bull. No. 16, U. S.'P. H. & M. H. S., 1903.
SMALLPOX AND VACCINATION 7
to adding more glycerin Avoukl bo the greater dilution of the virus, and, therefore, a larger proportion of negative takes. A higher percentage than 50 per cent, of glycerin soon renders the virus inert. The time required for the virns to ripen depends upon the temperature. Most of the non-spore-bearing bacteria perish in 30 days at 15° to 20° C. Approximately the same effect may be obtained at 37° C. in a few hours. At low temperatures the glycerin has practically no bactericidal effect. The process must always be controlled bacteriologically.
Vaccine virus should always be kept cold until used. The warmth of the doctor's pocket may be enough to destroy its potency in a few hours. The heat of the railroad car or post oflficc may soon render it impotent. This explains the difficulty sometimes encountered in obtain- ing potent virus during the summer months.
Substances other than glycerin are used for the purpose of purifying vaccine virus. Carbolic acid (0.5 to 1.0 per cent.), in addition to glycerin, is used with success in Japan, and to a large extent in this coun- try. Potassium cyanid, brilliant green, chloroform, chlorobutanol, etc., have been tried, with less success in practice.
Bacteria in Vaccine Virus. — Vaccine virus obtained from the skin always contains bacteria. However, these bacteria are, for the most part, harmless to man. They are commonly those that are found on and in the skin of the calf. The non-spore-bearing varieties are largely elimi- nated by the process of ripening. There are fewer bacteria in the typical unbroken vesicle than in the pustule or in a broken, crusty, inflamed eruption. Green virus may contain from a few thousand to over a million bacteria per cubic centimeter. The ripened, glycerinated virus con- tains much fewer, and these mostly harmless saprophytes. The number of such bacteria in the ripened virus may be taken as an indication of the care and cleanliness with which the virus has been prepared. In the LTnited States vaccine virus is required to have fewer than 50 bacteria per dose.
Noguchi ^ by painstaking methods obtained a bacteria-free vaccine virus, which may be propagated in the testicles of bulls or rabbits. Human beings react to' the testicular strain in an entirely typical manner, but this method has not been found practical for propagation on a large scale.
Seed Vaccine. — The seed virus may be obtained (1) from cowpox, (2) from smallpox, (3) by retro vaccination.
"Spontaneous" or casual cowpox occasionally occurs; that is to say, the disease appears to arise spontaneously because its origin cannot be traced. Casual cowpox comes either from another case of cowpox or from a case of smallpox. Cattle are not subject to smallpox, but, when smallpox virus is introduced into the skin of a calf, it produces cowpox.
Wour. of Exp. Med., June 1, 19L5, XXI, 6, p. 339.
8 DISEASES HAVING SPECIAL PROPHYLAXIS
When smallpox is thus converted into cowpox, it remains fixed as such, and never reverts to smallpox.*' Twenty-nine separate records of success- ful modification of smallpox virus into cowpox are found in the litera- ture; also a number of negative attempts. Some of the strains obtained in this way were used to vaccinate children with typical takes and adequate protection,
Retrovaccination consists in carrying the vaccine virus back from child to calf; better still, the virus may be passed from man through rabbit, monkey^ or other susceptible animal, and then again to the calf. Changing the species helps to maintain the activity of the vaccine virus for an indefinite time; furthermore, the change leaves behind cer- tain associated bacteria which may gather increased virulence by suc- cessive passage from animal to animal of the same species.
Propagation. — In the propagation of bovine virus young calves are preferred, because they are more manageable, the skin is more tender, and the eruption is therefore more abundant and typical. With young animals a milk diet may be used, which simplifies the problem of dust contamination from dry feed. If hay or fodder is used, it should first be autoclaved. Either heifers or bull calves are suitable, although the former are preferred.
The animals are held in quarantine for seven days, under observa- tion, to determine the absence of infections such as tuberculosis, glan- ders, foot-and-mouth disease, tetanus, fever, diarrhea or skin eruptions of any kind.
Before vaccinating the calf it is carefully cleaned, and the site of the inoculation is shaved and prepared surgically,^ but without the use of strong germicidal solutions, for the reason that they are apt to destroy the action of the vaccine virus. Cleanliness and asepsis are the watchwords. The area selected is usually the abdominal wall between the tip of the sternum and the groin, sometimes including the inner side of the thigh. The usual method is to make long, superficial incisions in the skin about one centimeter apart, and the seed virus is gently rubbed into these incisions. The calves must then be kept rigidly isolated in a special room, moderately lighted, free from dust, and screened to keep out insects. The temperature of the animal is taken several times daily and the eruption at each stage of the disease is closely watched and recorded.
The virus is usually taken from the animal about the fifth day. It is an advantage to take the virus early, in order to avoid contaminating infections which may occur when the vesicles maturate. Vaccine virus
* It is liighly significant that casual cowpox was formerly much more com- mon when smallpox was much more prevalent.
'' I used 3 scrubbings with soap and 3 tloodings with alcohol, at the Antitoxin and Vaccine Laboratory, Mass. State Dept. of Health.
SMALLPOX AND VACCINATION 9
taken after the eighth day is unreliable. Jeuner's golden rule was to take the virus before the areola appeared. Virus taken after the eighth day is apt to produce unduly inflamed or abortive vesicles, called spurious takes by the early vaccinators. Only typical and entirely characteristic vesicles should be removed. Before the virus is removed, the animal is chloroformed to avoid pain, and an autopsy is done as soon after the virus is removed as practicable. If the autopsy shows any lesions indicating infections other than vaccinia, the virus is discarded.
It is not wise in propagating vaccine virus to vaccinate too large an area. This favors infections by lowering resistance ; furthermore, less t^-pical eruptions are obtained than when the area vaccinated is moderate in extent. A yield of from 30 to 50 grams of pulp from one calf should satisfy the propagator.
Before the virus is taken the animal is placed upon a special table, the site of the vaccination exposed and given a very thorough washing and prolonged scrubbing with soap, and an abundant flushing with sterile water. The pulp is obtained by scraping the vesicles with a sharp spoon curette.
Glycerin (50 per cent.) in the proportion 1 to 4 is added at once to the pulp, and this is ground to a state of fine and uniform subdivision in a Csokar lymph mill, or simply by hand with a mortar and pestle. This glycerinated pulp is then allowed to age, and when purified by the action of the glycerin it is hermetically sealed in capillary tubes, or placed in small vials for the market.
METHODS OF VACCINATION"
Vaccination consists in transferring the virus of cowpox from one animal to the skin of another animal. The operation of vaccination con- sists of introducing vaccine virus into the skin. Under no circumstances must the vaccine virus be placed under the skin or subcutaneously. The operation may be compared to the transfer of a culture in a bacteriologic laboratory. Precisely similar precautions to prevent contamination must be used in both cases. Vaccination must be regarded as a surgical opera- tion. No person unfamiliar with surgical cleanliness should be per- mitted to perform this "little" operation.
The vaccine virus may be introduced in one of three ways: (1) by puncture, (2) by incision, or (3) by scarification.
Jenner used punctures or short incisions. Later blisters were raised upon the skin and the virus placed upon the abraded surface. The incisions w^ere then increased in number, and finally cross scratchings or scarifications were made.
10
DISEASES HAVING SPECIAL PEOPHYLAXIS
Puncture.— The simplest method is shallow ohliqiie pricking of the skin with a needle moistened with the vaccine virus; this gives little chance of contamination and the eruption is typical. The disadvantage is that the virus now used is diluted with glycerin, and therefore some- what attenuated, so that a few punctures may not give an adequate take.
Incision or Scratch. — The method advised and recommended is that of incision. Incision is the only method of vaccination permitted by the laws of Germany, and recommended by the Local Government Board of England. Incision, if not too deep, consists really of a series of punctures, and serves the same purpose. Incisions may be made with the point of a scalpel. I prefer to use a sterile needle. The incision or scratch should not be deep enough to draw blood, but a few drops do
no harm. It is rather difficult to control the depth of the incision with a scalpel, espe- cially if it is sharp. Scratching with a needle is much more easily controlled. Two. incisions should be made about one inch long and about an inch apart. The vaccine virus is first placed upon the skin in two small droplets about an inch apart. The point of the needle is now moistened in the droplet and as the scratch is made the needle carries the virus along with it into the little wound. With the flat of the needle the virus should be gently rubbed (not ground) into the scratch. It is important not to cause any unnecessary irritation so as to avoid attract- ing infections.
Scarification. — Scarification or cross-scratching should be prohibited by law. It is forbidden in Germany. The objection to scarification is that this method produces a relatively large abraded surface which is soon covered by a dry, hard crust of serum and blood, through which the erup- tion cannot pierce. The vesicles form a ring around the scarified area, leaving a central irritated wound inviting infection. Most of the cases of tetanus complicating vaccination occur in cases in which scarification was used. In this method favorable anaerobic conditions are produced under the crust or scab which forms over the abraded surface. The scarified area also leaves an unnecessary and unsightly scar (Fig, 1),
Fig. 1.
-Vaccknatiu.n ,Slai;.s Produced by ^Ietho;) OF Scarification. Note unnecessarv central scar.
SMALLPOX AND VACCTNATIOX 11
The Point of Election. — The outer surface of ihe left arm at about the insertion of the deltoid is the most convenient for tlie operator and the patient. This is the original site selected by Jcnner, and is less liable to severe glandular complications than other points. The skin here is easily made taut during the operation by grasping the under side of the arm. Inspection of the course of the eruption is also facilitated.
Flachs recommends the side of the chest at about the level of the sixth rib. in the axilla. Here the scar is not visible; but tiiis site is more objectionable than that recommended by I. IL Goldberger,* who uses the inner and back side of the arm.
The leg is sometimes selected to avoid disfigurement. The vaccina- tion scar should not be regarded as a deformity. To the sanitarian a typical vaccine scar is a sanitary dimple. The leg is more exposed than the arm to traumatism^, and, therefore, to complications. Dock refuses to vaccinate on the leg unless the patient will stay in bed until the vesicle heals. With babies in diapers and with young children it is exceedingly difficult to keep these parts clean. If the leg is selected, the vaccination should be done on the calf below the head of the fibula, and not on the outer surface of the thigh.
Number of Incisions. — This has an important bearing upon the probability of the take, as well as the protection. It is not wise to de- pend upon one. There is a definite relation between the number of vesicles and the degree and length of the immunity. See page IT. The German regulations of 1899 require at least four incisions, each one cen- timeter long and two centimeters apart. The Local Government Board of England directs that four vesicles should be produced, and that the total area of the vesicle formation shall not be less than one-half a square inch. ]\Iy own practice follows that of Dock, who makes not less than two incisions about an inch long and an inch apart; but in case of ex- posure to smallpox three or four such incisions are advisable.
The Operation. — The skin at the site of the operation must be sur- gically clean, but need not necessarily be treated with germicides. If such are used, they must be carefully washed away in order not to destroy the activity of the virus. A thorough preliminary scrubbing with soap and water is necessary for a dirty skin. "Washing with warm water followed by alcohol is usually enough. The alcohol should be per- mitted to evaporate before the vaccine is applied and the incision is made. In general, the less the skin is irritated the less the danger of complica- tions. Xeedles are particularly handy, as they may be flamed just before the operation, and are convenient in saving time when many people are to be vaccinated. The vaccine virus is gently rubbed into the incision, not ground in, and then allowed to dry. No dressing is necessary as long as the vesicle remains unbroken, but several layers of dry sterile
*y. r. Med. Jour., Dec. 25. 1020, 112, No. 6.. p. 10.35.
13 DISEASES HAVING SPECIAL PROPHYLAXIS
gauze held in place by adhesive plaster do no special harm, provided they are removed before pustulation. Pads, plasters, and shields of any sort are unwise, because by retaining heat and moisture they cause softening and breaking down; in other words, they act like a poultice.
The best dressing, is the unbroken skin, and then the crust (scab) which naturally forms. This permits frequent inspection and avoids undue heat and softening. If the pustule breaks or the crust comes off, or the take shows indications of secondary infection, frequent dress- ing with an active germicide is indicated. It is not good surgical technic to bind up any actively suppurating area for more than 24 hours.
Painting the vesicle with tincture of iodin, cauterizing the base with silver nitrate, or the application of carbolic acid, picric acid, and other active germicides does not diminish redness or shorten the course of the vaccinal eruption.
Bathing need not be omitted, nor any of the ordinary occupations, but ca-re should be taken not to soften the crust by water or sweat. Unnecessary use of the arm must be guarded against, as this increases the congestion, inflammation, and the chances of infection.
INDICES OF A SUCCESSFUL VACCINATION
The take must be typical and the clinical course characteristic, other- wise we have no assurance that the individual is protected against small- pox. The best indices of a successful take are: (1) the course of the eruption, (2) the general symptoms, and (3) the scar.
The importance of knowing the skin lesions of vaccinia were in- sisted upon by Jenner. Every vesicle, scab, ulcer, or irritated wound is not vaccinia. Xo confidence should be placed in doubtful or atypical takes. The characteristic features of vaccination are singularly alike. The clinical course of a primary vaccination is as follows :
Course of the Eruption. — The primary wound soon heals. Appar- ently nothing occurs for 3 to 4 days, which is the period of incubation. Then one or more small papules appear upon the skin where the vac- cine virus was introduced. The papule is small, round, flat, bright red, hard, but superficial. About the fifth day the summit of the papule becomes vesicular. The vesicle is at first clear and pearl-like. Umbilica- tion soon develops as the vesicle enlarges. A deep, red, and swollen areola surrounds the vesicle and grows wider as the lesion advances. This gives the picture of the "pearl upon the rose leaf" which consti- tutes the true Jennerian vesicle. By the seventh day the vesicle is full size, round or oval, flat on top, umbilicated, and contents clear. It is multilocular ; if pricked with a pin or accidentally opened only that portion of the lymph contained in the compartment opened will exude. By the eighth day it turns yellowish, the middle is fuller, following which the so-called second umbilication develops. Meanwhile the areola
SMALLPOX AND VACCINATION
13
deepens, widens, and may be swollen. The skin feels hot, is painful, and the axillary glands become enlarged and tender. About the tenth day the areola begins to fade and the swelling subsides. By tlie eleventh or twelfth day the pustule rapidly dries, leaving a brown, wrinkled scab, which finally drops off about the twentieth day. It should never be removed, as it forms the best dressing.
PUNCTURE
PUSTULE 9TH DAY
PAPULE -4"^" DAY
DESICCATION 12TH0AY
VESICLE 5'^**DAy
CRUST IBT"OAY
UMBILICATION7TMDAY FOVEATED SCAR
Fig. 2. — The Cotjrse of the Eruption (Diagrammatic).
The scar is at first red, finally turns white, with the pits or fovea- •tions so characteristic of true cowpox.
General Symptoms. — These vary. Malaise, loss of appetite, some- times nausea and vomiting, headache, pain in the muscles of the back, and other indications of a mild febrile reaction appear about the seventh day, and soon cease. The temperature may go to 38° or 38.5° C. as the vesicle ripens. The febrile reaction bears no special relation to the size and number of the vesicles or to the areola. The regional lymph nodes become enlarged and tender about the time the pustule forms. The nitro- gen elimination increases about the tenth day for a short time. The blood changes resemble those of smallpox, an early leukopenia and sec- ondary leukocytosis.
14
DISEASES HAVING SPECIAL rEOPHYLAXIS
Secondary vaccinations often run an accelerated^ milder, or modified course with shortened periods of incubation (see revaccination).
Vaccination certificates should be based upon observation of the course of the take. Modified reactions in revaccinations are to be inter- preted as successful takes, but their nature should be recorded — as im- mediate, or accelerated reactions, page 18.
THE IMIklUNITY
The immunity appears about the eighth day of the vaccination. Layet puts the point of safety at the ninth day, Burckhard at the elev-
Fi(,. 3. — VacciIv'IA. Course of the Eruption.
enth. These data are based upon the early work with variolation, when persons were inoculated witli smallpox at various periods following vac- cination. Sacco got only a local eruption by inoculating smallpox on the eightli to the eleventh days, and none after that.
Fig. 4. — Vaccinia. Course of the Eniption.
15
16 DISEASES HAYIXG SPECIAL PEOPHYLAXIS
Taccinia protects not only against smallpox, but also against vac- cinia. Curiously enough^ the degree and length of immunity appear to be greater against smallpox than against itself. Persons who have had smallpox may often be vaccinated successfully. It is irrational to at- tempt to fix a definite time for the duration of the immunity. This varies as in other infectious processes. It is known through experiment and experience that the immunity gradually wears off. The degree of protection is usually absolute for some years, and then gradually fades. Judged by successful revaccinations, it begins to disappear in 2 years and in 10 years is almost completely gone. In this, as in other diseases, immunity is a relative term. Smallpox itself does not always protect against smallpox. Some people have two and even three attacks of smallpox.^ Such cases, however, are exceptional, and it is also ex- ceptional to have smallpox occur in an individual who has been properly vaccinated.
Careful statistics collected in Japan since 1879 show quite definitely the gradual diminution of the immunit}', beginning with the second year after vaccination. Kitasato's table,^° based on 951 cases, is as follows:
SUCCESSFUL REVACCINATIOX AFTER
1 year 13.6 per cent.
2 years 32.9 " "
3 years 46.6 ^J |J
4 years 57.3
5 years 51.1
6 years 63.8
Weil, in 1899, reported 72.5 per cent, of successful revaccinations after seven years, 80 per cent, after eight years, 85 per cent, after nine years, and 88.6 per cent, after ten years. German Government reports show 90 to 93 per cent, successful revaccinations after 10 years.
It is commonly asserted that, if a revaccination takes, the subject was therefore susceptible to smallpox. While this is usually true, it does not necessarily follow. It is a still greater fallacy to state that, if a vaccina- tion fails, the subject is therefore immune. This view, may result in real harm. Vaccination may fail for many reasons — the operation may not have been properly done, or the virus may have been inert. Sometimes persons are unsuccessfully vaccinated three, four, or more times before a typical take is obtained.^^
A modified reaction must be regarded as evidence of immunity. Thus, the immediate reaction is a clear indication of immunity, the accelerated reaction of partial immunity.
» Jenner mentions "the lady of Mr. Gwinnett, who has had the smallpox five times." — Baron's "Life of Jenner," Vol. II, p. 265.
^"Jour. A. M. A., March 25, 1911, p. 889.
"One of my cases gave a history of having been unsuccessfully vaccinated five times. The' sixth attempt produced a typical primary take ^yith 21 vesicles.
SMALLPOX AND VACCINATION
17
There appears to be a (lofinite relation between the immunity con- ferred and the number of vaccination scars. There is also some evi- dence that the protection is directly proportional to the area of the local eruption. This question has not been carefully studied since the data contained in the final Report of the Royal Commission on Vaccination, which is summarized in the following table:
MORTALITY
OF POSTVACCINAL SMALLPOX IX OF SCARS
RELATION TO THE NUMBER
|
Number Scars |
of |
3,094 cases* (1836-51) |
10.661 cases* (1852-67) |
6,839 casest |
|
|
None |
' 21.7% |
39.4% |
|||
|
1 |
7.6 |
13.8 |
6.2% |
||
|
2 |
4.3 |
7.7 |
5.8 |
||
|
3 |
1.8 |
3.0 |
3.7 |
||
|
4 |
0.7 |
0.9 , |
2.2 |
* Final Report of the Royal Commission on Vaccination, 1896, paragraph 291. Dr. Thome, from data collected by Mr. Marson.
t Same Report, paragraph 293. Summary of cases apart from those of Mr. Marson.
One point needs emphasis : The degree and duration of the im- munity are directly proportional to the typical nature of the take. No reliance should be placed upon atypical reactions.
The immunity may be renewed ; two vaccinations are usually sufficient to protect for life.
The nature of the changes in the body which produce the immunity are not understood. In this sense vaccination is still an empiric pro- cedure. We now know of many analogous instances, however, where an active acquired immunity is induced by means of an attenuated virus. The immunity produced by vaccine virus does not depend upon an anti- toxin. The blood, however, contains specific antibodies, shown by the fact that the activity of vaccine virus is destroyed when mixed with equal parts of blood serum from a calf two weeks after successful vacci- nation.
WHEX TO VACCIXATE
The fact that the immunit}' wears off after a number of years makes it necessary to practice revaccination in order to afford a continuous protection. There is some difference of opinion as to just when it is best to vaccinate the second time. Ten years is too long a period, prob- ably, to depend upon in individual cases. One vear — advised by some — is shorter than necessary in most cases. The five-year interval of Japan
18 DISEASES HAVING SPECIAL PROPHYLAXIS
is good in many respects, but probably not better than revaccination in the twelfth year obligatory in Germany.
The best time to vaccinate is in the first year, at least before the second summer, and again at from ten to thirteen years. After this it is usually unnecessary to vaccinate again, unless there is particular danger of exposure to smallpox.
All persons exposed directly or indirectly to smallpox should at once be vaccinated and revaccinated until only an immediate reaction is obtained — unless they have had smallpox. There are no contraindica- tions to vaccinating babies immediately after birth, but takes are some- what less likely than at six months. Vaccination is accompanied by less reaction in young infants than in children, and less in children than in adults.
EEVACCINATION
The clinical picture of secondary vaccinations may be quite different from the typical take following a primary vaccination. These altered reactions were known in the time of Jenner, but were lost sight of until recently rediscovered, and their significance realized from studies in anaphylaxis.
Revaccinations may be divided into three groups: (1) they may run an unaltered course resembling primary takes in all respects, showing that immunity to cowpox had disappeared; (2) they may run a somewhat more rapid course in which the period of incubation is shortened and in which the height of the eruption occurs about the sixth day, this is known as the accelerated reaction; or (3) they may run a very much shortened, milder, and rapid course. The eruption may be only a small papule which does not develop into a vesicle and slowly disappears; the period of incubation is about 24 hours. This is known as the immediate reaction and resembles a cutaneous tuberculin reaction in many respects. Every gradation occurs between an immediate reaction and a primary take. These altered reactions are significant and have been studied especially by von Pirquet and are shown graphically in Fig. 5. _ _
Both the immediate and the accelerated reaction are indications of immunity and therefore should be considered as successful takes. The immediate reaction may be put to practical use in order to distinguish smallpox from chickenpox.^^ Thus, Tieche has shown that smallpox virus introduced into the skin of a person immunized by vaccination will show the typical immediate reaction ; whereas the virus of chicken- pox is invariably negative. This test can be freed of all possible danger by heating the virus to 60° C. for 30 minutes, which does not seem to affect the reaction. " See also page 395.
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20 DISEASES HAVING SPECIAL PROPHYLAXIS
CLAIMS FOR VACCINATION
1. "Duly and efficiently performed it will protect the constitution from subsequent attacks of smallpox as much as that disease itself will." "
2. It protects the individual against smallpox for a period which has not been determined mathematically for the individual, but which averages about seven years.
3. The protection may be renewed by a second vaccination.
4. Persons successfully vaccinated on two occasions are usually immune against smallpox for life.
5. Vaccination and revaccination systematically and generally car- ried out confer complete protection to a community or a nation. In other words, while the individual protection is not always lasting, the communal protection is absolute.
6. A person vaccinated once and at a later time contracting small- pox as a rule has the disease in a less serious form than unvaccinated persons (varioloid).^* The degree of favorable modification of smallpox is in inverse proportion to the period of time elapsing between the vac- cination and the attack of smallpox.
7. The beneficial effects of vaccination are most pronounced in those in whom the vaccine affection has run its most typical and perfect course.
■ , VACCINATION OF EXPOSED PERSONS
The question frequently arises whether persons exposed to smallpox should be vaccinate'd. The effect of vaccination during the period of incubation of smallpox is very interesting, and may be summed up as follows :
1. Vaccination just before or during the primary fever of smallpox does not influence the disease.
2. If the vaccination is done during the last stage (9th to 14th day) of the period of incubation of smallpox, the two infections run their course side by side without influencing each other.
3. If it is done about the sixth or eighth day of the period of in- cubation the vaccination takes and may modify the severity of the smallpox.
4. Vaccination done at the beginning of the incubation period, in
" "I never expected that it would do more, and it will not, I believe, do less." — Jenner. Baron's Life, Vol, II, p. 135.
"The term varioloid was introduced by Thompson in 1820 to describe the mild and modified form of smallpox occurring after vaccination. The eruption in varioloid does not mature and disappears more rapidly than in variola.
Yolfert, Dornbleuth, and Harden showed that one vaccination was not always sufficient protection against smallpox for a lifetime, that revaccination was necessary and that the clinical manifestations of this vaccination are as different from those of the first vaccination as varioloid is from variola.
SMALLPOX AND VACCINATION 21
time to have the vaccine eruption reach maturity before the smallpox begins, will prevent or abort the disease.
As we can never be quite sure just what stage in the period of in- cubation a given case may be in, it is always advisable to vaccinate exposed persons. Furthermore, little harm will be done if it is too late and the vaccine eruption is added to the smallpox. Indeed, Hanna ^'^ presents claims to the effect that there is evidence of mitigation of the severity of smallpox when vaccination is performed at any time after infection up to the day of onset and even afterward.
DANGERS AND COIklPLICATIONS
The alleged danger from vaccination has been greatly magnified by the antivaccinationists. However, vaccination is not always a harmless procedure; it must be looked upon as the production of an acut^e infec- tious disease, and, although the disease is always mild and benign, it must not be treated as trifling. The chief danger lies in the fact that we have produced an open wound, which is subject to the complications of any wound. Even a pin prick or a razor scratch may result in death. While the aggregate number of deaths resulting from the complications of vaccination were considerable, the Individual risk is now so small as to be disregarded, especially when proper precautions are taken. Many of the infections after vaccination occur in those in whom the regard for cleanliness is slight, and who neglect the care of the wound. In recent years, owing to the improved quality of the vaccine virus and the introduction of aseptic methods, a bad sore arm is a rare occurrence, and serious complications still rarer. The danger connected with vacci- nation is infinitesimal when compared with the benefit conferred.
The following complications need consideration :
Auto Vaccination. — This is usually due to scratching the virus with the finger into the nose, the mouth, the mucous membranes, or any part of the skin. When carried into the eye it may cause blindness. Physi- cians sometimes vaccinate their lips by blowing into vaccine tubes. In vaccine establishments accidental vaccination of the hand is common.
Generalized Vaccination. — This is sometimes reported, but is in my experience a mistaken diagnosis. A generalized eruption of cowpox is exceedingly rare, if it ever occurs. I have seen it once in the calf after intravenous injection of a large amount of the virus, in which case there was a prolonged period of incubation.
The eruption is strictly confined to the point of vaccination. Satellite vesicles sometimes develop in the immediate neighborhood, owing to the spread of the virus into minute nicks in the epithelium.
^'Public Health, July, 1910, XXIII, No. 10, p. 351.
23 DISEASES HAVING SPECIAL PEOPHYLAXIS
Wound Infections, such as ulcers, gangrene, erysipelas, abscesses, lymphangitis, suppuration of the axillary glands, and other septic infec- tions are now exceedingly rare, and demand the usual surgical measures to prevent their occurrence.
Impetigo contagiosa occasionally occurs and may be a serious com- plication of vaccination^ trspecially the rare bullous impetigo or pemphigus which is attributed to special susceptibility or chance infec- tion and not to the vaccine virus.
(Syphilis, tuberculosis, and leprosy were formerly thought of as possibilities when human virus was used, but these are not to be feared with the use of bovine virus.)
Tetanus. — Tetanus deserves a special word. This serious infection sometimes complicates a vaccination wound just as it may any wound. When we consider the many millions of vaccination, wounds, many of which are neglected surgically, it is no surprise to learn that tetanus occasionally occurs as a postvaccinal complication. Acland is acquainted with only one instance in more than five million consecutive vaccinations in England, and even in this one there was no evidence that the tetanus was in the vaccine virus. Over 31,000,000 doses of vaccine were used in the United States from 1904 to 1913 inclusive, yet only 41 authen- ticated cases of tetanus occurred subsequent to vaccination.^^ A study of these cases makes it clear that the infective principle was not in the vaccine virus, but was received ten days or more after vaccination, owing to the prolonged period of incubation (20.7 days) and the high mortality (75.2 per cent.). The pernicious method of vaccination by scarification was used in almost all cases of tetanus following vaccination. Many of the cases give a history of having the vaccination scab or crust removed in some way, thus permitting infection of the wound with a re-formation of the crust and the establishment of an anaerobic condi- tion. The fact that lack of care is an important factor in postvaccinal tetanus is indicated in the figures from the United States Army and Navy with a record of millions of vaccinations without a single case of tetanus. At the Hygienic Laboratory at Washington vaccine virus representing over two million vaccinations has been examined without finding tetanus. Special tests for tetanus are required by Federal regula- tions of every lot of vaccine virus before it is placed upon the market. In the Vaccine Laboratory of the State Department of Health of Mas- sachusetts, these tests are conducted in accordance with the Eegulations ^'^ of the U. S. Public Health Service of October 1, 1919, as follows:
Samples of the virus from each calf are tested separately. Only
*'J. F. Anderson: United States Public Health Keport, Reprint 289, July 16, 1915.
"Edward Francis, "Laboratory Studies on Tetanus," Hvgienic Laboratory Bull., No. 95, August, 1914, U. S. Public Health Service. Also G. W. McCoy and Ida A. Bengston, Hyg. Lab. Bull. No. 115, Oct., 1918.
SMALLPOX AND VACCINATION 23
ground glycerinated piil[) ki'{)i without preservative for at least 7 days at a temperature of 10° C. or higher is used for the tetanus test. This is to permit tiie destruetion l)y the glycerin of the most of the frail hat'teria. Tlie test virus must not contain pliciiol or preservative other than glvicrin. Two euhie centimeters of the virus is planted in each of four Smith fermentation tuhes, each containing at least 25 cubic centimeters of meat infusion hrotli. The::e tubes are heated to 100° C. for thirty minutes just before planting in order to expel the oxygen of the air. The tubes are incubated at .'>7° C. and inspected daily; those showing gas or growth in the closed arm are used to inoculate mice or guinea pigs with one cubic centimeter of the unfiltered broth, not less than tvi'enty-four hours after growth in the closed arm and also nine days after planting. If the animals show symptoms of tetanus, the entire batch of vaccine is discarded. Or:
(a) Plant 0.25 c. c, virus in plain broth fermentation tube. In- cubate at 37° C and inject 0.25 c. c. of the growth at the end of 9 days subcutaneously into a mouse.
(b) Plant 0.25 c. c. virus into fermentation tubes of glucose bouillon and incubate immediately. Inject 0.25 c. c. of the growth at the end of 9 days subcutaneously into mice.
(c) Plant 0.25 c. c. vaccine virus into fermentation tubes of glucose bouillon, heat at 60° C. for one hour and then incubate. Inject 0.25 c. c. of the growth into mice at the end of 9 days.
(d) Plant 0.25 c. c. vaccine virus into fermentation tubes of ordi- nary bouillon, containing a bit of sterile tissue, and inject 0.25 c. c. of the growth at the end cf 9 days into mice.
(e) Inject 0.25 of the vaccine virus subcutaneously into guinea-pigs. If tetanus spores are present in the virus, one of these four methods
is almost sure to detect them. The tests are made in duplicate so that a total of 2.5 c. c. of the virus is thus tested.
The occurrence of occasional stray tetanus spores in vaccine virus was demonstrated by Carini.^^ Such vaccine, however, had proved en- tirely harmless in thousands of cases. Francis also showed that vaccine virus purposely contaminated with tetanus spores will not produce tetanus in monkeys, although it will produce typical "takes."
Glycerin does not destroy the tetanus spore. While the occa- sional danger cannot be denied, it is plain that postvaccinal tetanus can usually be laid to improper methods of vaccination and to lack of care of the vaccination wound.
To prevent tetanus complications it is important to avoid scarifica- tion and irritation, to avoid the use of shields and bandages which favor anaerobic conditions, to require the patient to use strict cleanliness, and to use vaccine virus that has been properly prepared and tested.
"^Centralhl. f. BaJct., Orig. 1904, XXXVII, p. 1147.
24 DISEASES HAVING SPECIAL PEOPHYLAXIS
Foot-and-Mouth. Disease. — The infection of foot-and-mouth disease has in one instance been demonstrated as a contamination of vac- cine virus.^^ It is, however, impossible to convey foot-and-mouth dis- ease to man through cutaneous inoculation. While no harm has been done to man, the contamination is undesirable, and vaccine virus is tested from time to time to assure its freedom from this infec- tion (page 406).
As an illustration of how seldom complications are caused by vac- cination we have the results of Germany, where in thirteen years (1885- 1898) 32,166,619 children were vaccinated. Of these 115 died within a few weeks or months after the Operation, presumably of injuries in- cidental thereto. Of these at least 48 probably did not die as a direct result of the vaccination.
The figures of recent years are still better, for it is now exceedingly rare for a death to be recorded as directly due to vaccination.
Ten million vaccinations in the Philippine Islands were done under the direction of American health authorities without the loss of life or limb. Of the millions of vaccinations done in the army and navy during the World War, there is not a single record of serious result. This clearly indicates that with the use of a carefully tested virus and efficient technic, the danger is nil.
THE GOVEENMENT CONTROL OF VACCINE VIRUS
By the law of July 1, 1902, the vaccine virus sold in interstate traf- fic in the United States must come from a licensed manufacturer. These licenses are issued by the Secretary of the Treasury only after a careful inspection of the plant, personnel, and product by a competent government officer. The licenses are good for one year only, and are reissued only after reinspection. The government regulations require each lot of vaccine virus to be examined carefully by modern bacterio- logical methods to determine the number of bacteria, and special tests must be made to determine the absence of pathogenic microorganisms. These tests include animal inoculations, as well as cultural methods. Special tests for each lot of vaccine must be made to determine the presence or absence of streptococci, tetanus spores, the gas bacillus, and other pathogenic microorganisms, etc. The government does not guaran- tee the purity and potency of each package of vaccine virus, but through its inspections and frequent examinations of the virus on the market every confidence may now be had in the vaccine virus propagated by licensed manufacturers in this country.
"Mohler and Rosenau, U. S. Dept. of Agriculture, B. A. I. Circular 147, June 16, 1909.
SMALLPOX AND VACCINATION 25
THE UNITY OF COWPOX AND SMALLPOX
The unity or duality of these two diseases has been the subject of much contention. Jenner originally considered cowpox to be a modified smallpox.20 The successful experiments in Germany, England, and this country, in which smallpox has actually been modified by passing vario- lous matter through calves has proved positively that we are dealing with two forms of one disease. Much of the vaccine virus used during the past hundred years was originally obtained from cases of casual cow- pox. This virus has been shown by experience and experiments to pro- tect against smallpox, which again makes it highly probable that we are dealing with one disease. See also page 8.
It seems plain that the so-called casual cowpox has its origin from smallpox through accidental inoculation in milking cows by persons having or recovering from smallpox. Once started, the propagation of the modified virus from cow to cow would be comparatively simple.
COMPULSORY VACCINATION
Vaccination affords a high degree of immunity to the individual, and a well-nigh perfect protection to the community. To remain unvac- cinated is selfish in that by so doing a person steals a certain measure of protection from the community on account of the barrier of vac- cinated persons around him.
The laws ^^ and regulations relating to vaccination in the several states of the United States show marked lack of uniformity. Compul- sory general vaccination can be said to exist by law only in Kentucky, Philippine Islands, and Porto Kico.^^ Arizona, Hawaii, Maryland, New Mexico, and North Dakota have laws requiring vaccination of children. Most states or cities have laws requiring vaccination before admission to the public schools.
Decisions in the various courts in the United States have held com- pulsory vaccination to be legal. A decision of the Supreme Court of the United States (Henning Jacobson vs. The Commonwealth of Massa-
^" Smallpox is a disease subject to mutations. Since 1898 a mild form of smallpox has existed in this country with a death-rate of about 0.5 per cent. This mild form shows little tendency at present to increase in virulence. Chickenpox itself may belong to the smallpox family. The two diseases are sometimes indistinguishable at the bedside. Jenner always considered cowpox and smallpox as modifications of the same "distemper," and that in using vaccine lyjuph he was impregnating the constitution with the disease in ita mildest form instead of propagating it in its virulent and contagious form. Alastrim, kaffirpox, milkpox, etc., are aberrant forms of smallpox occurring in the tropics, and for public health purposes should be regarded as variola vera. These irregular forms of the disease need further study.
^'Kerr, J. W., "Vaccination, and Analysis of the Laws and Regulations Relating Thereto in Force in the United States." Public Healtlv Bull. 52.
-^Massachusetts, in 1809, was the first state to enact -legislation relative to vaccination.
26 DISEASES HAVING SPECIAL PROPHYLAXIS
chusetts, April 1, 1905) upheld in every respect the statute, the validity of which was questioned under the Constitution :
"The liberty secured by the Constitution of the United States . . . does not impart an absolute right in each person to be, at all times, and in all circumstances, wholly freed from restraint. Pieal liberty for all could not exist under the operation of a principle which recognizes the right of each individual person to use his own, whether in respect to his person or his property, regardless of the injury that may be done to others."
Theoretically it would be ideal if all persons submitted to vaccina- tion and revaccination voluntarily. But experience has shown that this is impractical, and, wherever tried, has failed. The best results have always been obtained where vaccination has been compulsory, and, in my judgment, this is the only present means by which smallpox may be eliminated.
The world may learn a valuable lesson from the splendid results ob- tained in Germany through compulsory vaccination and revaccination. In England the "conscience clause" allows many persons to remain un- vaccinated and thereby seriously diminishes the effects of the vacci- nation laws of that land. In Minnesota the state health authorities be- came weary of the clamor against compulsory vaccination and assisted in having the law repealed. They said, in substance, to the people of the state: "Take your choice. Be vaccinated and protect yourself, or run the risk of contracting smallpox; if you get it, it is your own fault."
There is now much smallpox widely distributed in the United States, among a large non-vacinnated portion of the population.
INOCULATION OR VARIOLA INOCULATA
[Variolation]
The practice of inoculation or variolation must be carefully distin- guished from that of vaccination. By inoculation we mean the introduc- tion of smallpox virus into the skin of man. The disease thus pro- duced is usually mild, but is nevertheless true smallpox, and just as con- tagious as smallpox.
This phase of the subject may be made clearer by considering small- pox as existing in three forms: (1) variola vera or true smallpox; (2) variola inoculata or inoculated smallpox; (3) vaccinia, cowpox, or modi- fied smallpox. The differences between these affections are shown in the table on the following page.
Emphasis must be placed on the fact that variola inoculata, while usually a mild disease, is just as communicable as true smallpox, and those who contract the disease in this way get true smallpox, sometimes in serious or fatal form. Inoculation, therefore, protects the individual but endangers the community.
SMALLPOX AND VACCINATION
27
|
Variola Vera |
Variola Znocnlata |
Vaccinia or Cowpox |
|
True smallpox. |
Inoculated smallpox. |
Modified and attenuated small- pox. |
|
Occurs only in man. |
Occurs in man and monkeys. |
Man, nionlceys, cattle, puineu- piKs, raljtjits, rats, camels, and many other mammals. |
|
High mortality. |
Milder; rarely fatal; about 1 in 500. |
Very mild ; never fatal. |
A general eruption, often confluent or liemor- rhagic.
Highly contagious.
A local and a general eruption, fewer .p,ustules (rarely over: 200); seldom confluent or hemorrhagic.
Equally highly contagious.
Period of incubation 12-8 days. 14 days. I
Always local and conflned to the site of the vaccination.
Not contagious — contracted only by mechanical transfer of vaccine virus.
3-4 days.
Inoculation is a very old custom. It was practiced by the Chinese from time immemorial. The method was introduced into western civili- zation through Lady Mary Wortley Montagu, who learned of the method at Constantinople and had her own boy "engrafted" with successful re- sult. In 1717 Lady Montagu wrote her now famous letter to her friend Sarah Chiswell, and the practice soon became popular in England (1721) and spread to America and the Continent.^^ It was introduced into this country by Dr. Zabdiel Boylston at Boston. But the dangers were early realized and inoculation was soon replaced by vaccination. According to Plehn, inoculation is still practiced in central Africa.
The method of inoculation is precisely similar to that of vaccina- tion. The matter is obtained from the vesicle or pustule of a case of smallpox. This material is then introduced into the skin by means of a puncture, an incision, or through an abraded surface. The Chinese inoculate usually by plugging the nostrils with cotton previously sat- urated with a mixture of water and pustular-crustaceous matter taken from the eruption of a smallpox patient; less commonly by blowing the crushed fresh crusts into the nostrils through a bamboo pipe.
Following the inoculation of smallpox virus a local eruption appears on the fourth day at the site of the inoculation. This local eruption resembles vaccinia but develops more rapidly. Constitutional symptoms appear on the evening of the seventh or the morning of the eighth day following the inoculation. These symptoms resemble the onset of true smallpox and are rigor, headache, vomiting, and fever. The local erup-
" The practice of inoculation had been published in England as early as 1714 by Dr. Timoni of Constantinople; at Venice in 1715 by Pylarini, and in the same year in London by ilr. Kennedy, a surgeon who had been in Turkey. Its adoption and subsequent ditfusion, however, were due to Lady Mary Wortley Montagu.
28 DISEASES HAVING SPECIAL PEOPHYLAXIS
tion subsides on the appearance of the febrile symptoms but at the same time the general eruption breaks out. The crop is usually discrete, mod- erate in number, but runs the usual course through papule, vesicle and pustule formation.
Inoculation has fallen into disuse only because we have vaccination. There are conceivable emergencies in which the practice would be justi- fied. For example, on board ship or on an island or isolated place, in the absence of vaccine virus. Under such circumstances it would be essential to inoculate ever3^body at the same time.
The inoculation of smallpox will always remain for the student of hygiene one of the most interesting episodes in the develop- ment of preventive medicine. It illustrates in the clearest manner some of the fundamental phenomena of infection, susceptibility, and immunity. It was animal experimentation on a huge scale, the like of which we shall never see repeated on man as the subject. It is now a matter of regret that for the sake of science better advantage was not taken of the data.
PREVALENCE OF SMALLPOX
It is very difficult for us now to realize that smallpox was once much more common than measles and much more fatal. Many of those who recovered were disfigured for life, left blind, or with some other serious consequence of the disease. For centuries smallpox was one of the greatest scourges. It depopulated cities and exterminated nations. In Europe alone, where its ravages were comparatively slight, it killed hundreds of thousands yearly. In the 18th century, of which we have the best records, almost everybody had it before he grew up. Parents often exposed their children to the disease in order to be through with it, just as they now sometimes do with the minor contagious dis- eases.
Smallpox was formerly a disease of children. It was called Kinder- hldttern. Since vaccination protects the child, smallpox has now be- come more prevalent among adults.
The distinguished mathematician, Bernouille, estimated that 15,000,- 000 people died of smallpox in 25 years in the 18th century. It has been estimated that 60,000,000 people died of smallpox during that century. Haygarth gives an account of a smallpox epidemic in Chester, England, population 14,713. At the termination of the epidemic there were but 1,060 persons, or 7 per cent, of the population, who had never had smallpox. Many similar instances are cited in the literature. The French physician de la Condamine (1754) said that "every tenth death was due to smallpox and that one-fourth of mankind was either killed by it or crippled or disfigured for life." Sarcone (1782) estimated the
SMALLPOX AND VACCTNATTOX 29
number of persons in Italy who tJufTered from smallpox as 90 j)or cent, of the population.
Smallpox was introduced into the western hemisphere by the Span- iards about fifteen years after the discovery of America. In Mexico within a short period 3,500,000 persons are said to have died of the disease (Chapman). Catlin (1S41) states thai of 1-^,000,000 American Indians 6,000,000 fell victims to smallpox. In Iceland, in 1707, 18,000 perished out of a population of 50,000, that is, smallpox iilfled 36 per cent, of the total population in one year.
A good example is that of Boston in 1752, population at that time 15,684. Of this number 5,998 had previously had smallpox. During the epidemic 5,545 persons contracted the disease in the usual manner, and 2,124 took it by inoculation. One thousand eight hundred and forty- three persons escaped from the town to avoid infection. There were, therefore, left in the city but 174 persons who had never had smallpox.
Smallpox is still as serious as it was in former times. Thus, in five years, from 1893-1897, 346,520 persons died of smallpox in sixteen countries. Of this number Russia alone lost 275,502. These figures are the more terrible when it is realized that these lives might have been saved by the use of a simple prophylactic measure within reach of all.
EPIDEMIOLOGY
Few of the acute infectious diseases show such a complete indepen- dence of conditions such as race, climate, soil, age, sex, and occupation, sanitary surroundings, etc., as does smallpox. It thrives wherever the contagion is carried, and wherever it finds susceptible people. Prob- ably no one is naturally immune. The susceptibility of an unvaccinated population varies, because a smallpox outbreak leaves so many immune. This is one reason why the disease recurs in waves. The mortality varies greatly in difEerent epidemics. At times it is less than one per cent.; it frequently reaches thirty per cent, and over.
From 1897-1912 the mortality in the United States varied from 0.34 per cent, to 6.2 per cent.; in 1895 it was 20.84 per cent., and following that 0.5 per cent. These differences occurred in the prevaccination era as well as now. There seem to be two distinct strains in the United States, one the classic smallpox of the text books, the other a very mild form.
The epidemiology of smallpox bears no relation to improved sanita- tion, which has diminished the prevalence of plague, typhoid, cholera, and has practically subdued typhus and relapsing fever. It is evident that general sanitation could not affect contagious diseases like small- pox and measles. Smallpox spares neither the high nor the low, the rich Dor the poor, the clean nor the dirty; before the days of vaccination it
30 DISEASES HAYIXG SPECIAL PEOPHYLAXIS
counted many kings, queens, and princes among its victims. George "Washington contracted smallpox in the West Indies.
MODES OF INFECTION
We are still ignorant of the precise mode by which smallpox is con- veyed. The view generally held is that the infection is air-borne and enters the system through the respiratory mucous membranes. It has been surmised that a local lesion may be produced in this favorable soil, the so-called "propustule," from which general infection through the blood takes place. The blood infection is marked by a sharp onset (the initial symptoms), and the skin eruption is embolic in character. The objection to this view is that a careful search at 54 autopsies in Boston by Councilman and his colleagues failed to find such a propustule.
The Chinese inoculate the disease by placing variolous matter in the nostrils, but the disease so produced is said to resemble variola inoculata.
The virus of smallpox is contained in the skin lesions. Of this we have experimental evidence. It is also supposed to be in the expired air. This, however, has never been experimentally proved and is doubt- ful. The disease is contagious before the eruption appears. It is even believed to be communicable during the period of incubation. Small- pox has always been taken as the type of the contagious diseases; the contagion appears to be the most "volatile" of any of the diseases of man with the possible exception of measles and influenza. This volatil- ity, however, has been over estimated, and, while probably an air-borne infection, the radius of danger is contracted. English observers have long taken the vicAv that smallpox may be blown for great distances, and they attribute the prevalence of smallpox to the windward of hos- pitals as an indication that the virus may be carried down the wind. My experience with the disease teaches me that the danger from such a source is practically nil. One may safely live next door to a small- pox hospital that is well screened and properly managed. The influence of flies and other insects, or surreptitious visiting, may account for the spread of this disease outside of hospital walls.
In addition to more or less direction contact, smallpox may be spread indirectly in a great variety of ways. The secretions from the mouth and nose doubtless contain the infection, and, while suspicion has not particularly fallen upon the feces and urine, it is probable that all the secretions and excretions from the body may be infective at some time throughout the disease, or during convalescence. Toys, pencils, spoons, cups, towels, handkerchiefs, bedding, and objects of the greatest variety that have in any way come in contact with the patient may carry the infection. Under favorable circumstances the active principle may prob-
SMALLPOX AND VACCINATION 31
ably live for a considerable time upon I'omites, altlu)ii;^di tbc praetieal danger from this source is not very great.
Smallpox is not usually considered an insect-borne disease, but it is highly probable that a fly lighting upon a smallpox patient and getting its proboscis, feet, and other portions of its body smeared with the variolous matter, and then flying to a susceptible person, could thus readily transmit the infection. Other insects may by such mechanical transfer play a similar rule.
RESISTANCE OF THE VIRUS
It is generally, and doubtless correctly, assumed that the active prin- ciple of variola has approximately the same resistance to external con- ditions as vaccine virus. This assumption is confirmed by experimental evidence, which shows that the virus of smallpox is somewhat more readily destroyed than the virus of cowpox. Scientific data concerning the viability of variolous matter is meager, owing to the fact that this question can only be settled by prolonged and repeated experiments upon monkeys. Brinckerhoff and Tyzzer ^^ found that variolous virus is less resistant to desiccation than vaccine virus; that variolous virus does not pass a Berkefeld filter and is attenuated by long exposure to 60 per cent, glycerin.
In general it may be said that variolous virus is killed by exposure to ordinary germicidal substances, both liquid and gaseous, in the strengths and time commonly employed. It succumbs in fact before the average non-spore-bearing bacteria.
There is an exception to this statement in the case of carbolic acid and the coal-tar disinfectants. McClintock and Ferry -^ have shown that such germicides as carbolic acid, cresols, and the like do not destroy the virulence of vaccine' virus in 0.5 per cent, solutions in five hours' ex- posure.-® Noguchi found that 1 per cent, phenol has no injurious ef- fect upon emulsions of the testicular strain of vaccine virus. The in- ference is allowable that this class of disinfectants cannot be relied upon to prevent the spread of smallpox.
Glycerinated virus is very susceptible to heat.
SMALLPOX IN TEE VACCINATED AND UNVACCINATED
The experience of over one hundred years offers convincing proof of the pronounced difference in the mortality and morbidity from small- pox in the vaccinated and the unvaccinated.
""Studies upon Experimental Variola and Vaccinia in Quadrumana," Jour. Med. Research, Vol. XIV, No. 2, Jan.. 1906, pp. 223-3.59.
^Jour. of the Amer. Public Health Assn., June, 1911 (Vol. I, No. 6), p. 418.
^ Jo«r. Exp. Med., March 1, 1918.
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34
DISEASES HAVING SPECIAL PROPHYLAXIS
In countries like Germany. Sweden, Ireland, Scotland, the Philip- pine Islands, Porto Eico, and England, where vaccination is more or less compulsory, there is comparatively little smallpox. In countries, like Belgium, Russia, Austria, and Spain, which have no compulsory vaccination laws, smallpox yearly claims many victims. See the follow- incf table :
TABLE
1. — DEATHS FROM SMALLPOX IN COUNTRIES WITH COMPULSORY VAC- CINATION AND THOSE WITHOUT COMPULSORY VACCINATION
Population
Sweden* 4,746.465
Ireland* 4,808,728
Scotland* 4.013,029
Germany* 47,923,735
England* 28,247,151
Switzerland 2,922,430
Belgium 5,940,365
Russia 92,822,470
Austria 23,000,000
Italy 29,717,982
Spain 11,864,000
|
Smallpox Deaths |
Average of Deaths |
Average per |
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1887 |
1888 |
1889 |
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9 |
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112 |
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23 |
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9,591 |
14,138 |
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11,220 |
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8,472 |
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963 |
* Compulsory vaccination.
April 8th, 1874, Germany passed a general compulsory vaccination and revaccination law. The law requires the vaccination of all infants before the expiration of the first year of life, and a second vaccination at the age of twelve. Since this law went into effect there have been no epidemics of smallpox in Germany, despite the fact that the disease has been frequently introduced from without. In 1897 there were but 8 deaths from smallpox in the entire German empire — population 54,- 000,000. Since then long periods have passed without a single death from smallpox. From 1901 to 1910 there were only 380 deaths from smallpox in Germany; during the same period there were 4,286 deaths from smallpox in England and Wales, with only about half the popula- tion of Germany; furthermore, many of the deaths in Germany were in foreigners. Thus in 1909, out of 26 deaths from smallpox, 13 were foreigners, 11 of whom were Russians. In 1911, there were 288 cases of smallpox in the German Empire. Of these, 119 were of foreigners. In 1912, there were 340 cases, of which 153 were foreigners. In 1913, there were only 90 cases, of which 39 were in foreigners. During the World War, the large number of Russian prisoners in Germany caused a marked increase of smallpox in the civil population. In the huge German army there were only two deaths from smallpox from 1874 to 1914. One of these was a reservist who had not been successfully vacci- nated. Germany has demonstrated how to utilize Jenner's great dis- covery.
SMALLPOX AND VACCINATION 35
ISOLATION AND DISINFECTION
Isolation and disinfection are only secondary measures in prevent- ing smallpox. They cannot be regarded as substitutes for vaccination.
Isolation should be carried out vrith strictness for the reason that smallpox is one of the most contagious of the communicable infections. While the patient should be isolated, it is not necessary to isolate the hospital by banishing it to an inconvenient or undesirable location. There is, in fact, no good reason why a smallpox hospital should not be one of the units of the general hospital for communicable diseases. In any event, there is no danger from a smallpox hospital situated upon a highroad or near other habitations, provided always proper precautions are taken to prevent the spread of the disease.
The smallpox hospital should not be a pesthouse, but should be as inviting and attractive as economic conditions Justify. Smallpox should not be treated in the home. From the standpoint of prophylaxis the hospital is the logical and best place to care for this and other communi- cable infections. If smallpox is treated in the home, this should only be permitted if skilled nursing and trained attendants can be provided.
The room in which the smallpox patient is isolated should be simply furnished to facilitate cleanliness and to permit purification. It must be well screened and free from insects and vermin of all kinds. The room should be well ventilated. This may be accomplished by an open fireplace, in which case the contagium, if contained in the outgoing air, is burned in exit.
The nurse attending a case of smallpox should also be segregated, and all visiting should be strictly interdicted. A separate kitchen should be provided and care should be taken that the dishes be scalded and remnants of food burned.
Bedding, underwear, towels, and other objects should not leave the sick room unless they are first boiled, steamed, or immersed in a suitable germicidal solution, such. as bichlorid of mercury, 1-1,000, or formalin, 10 per cent. Carbolic acid should not be trusted.
For terminal disinfection cleansing of surfaces with a germicidal solution is much surer than gaseous fumigation. Objects particularly contaminated or soon to be used by others should be given a separate and special disinfection. Finally, the room should be thoroughly cleansed, aired, and sunned.
The patient must be regarded as the source and fountainhead of the infection, and measures should be used at the bedside to prevent the surroundings from becoming contaminated. Cloths, cotton, and other dressings that become soiled with the contents of the vesicles and pustules after they break should be burned. The urine and feces may
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38 DISEASES HAVING' SPECIAL PEOPHYLAXIS
be disinfected with chlorinated lime. The sputum and discharges from abscesses should be collected on cheap cloths and burned. As a rule, smallpox patients are not dismissed from quarantine until desquama- tion has ceased. This may be favored by the use of warm baths and a generous use of glycerin soap, also by anointing the skin with vaselin or a bland oil. Special attention should be given to the hair, which should be well shampooed; to the interdigital spaces, and the fingernails, as well as to all folds of the skin, before the patient is released.
The management of a smallpox epidemic is discussed on page 495,
EEFEBENCES
Jenner^ Edward : "An Inquiry into the Causes and Effects of the Yariolae Vaccinae, a Disease Discovered in Some of the Western Counties of England, Particularly Gloucestershire, and Known by the ISTame of the Cowpox." London, 1798,
Brit. Med. Jour., May 23, 1896 (Jenner Centenary Number).
Brit. Med. Jour., July 5, 1902 (Special Vaccination Number).
Report of the Royal Commission on Vaccination. 1897.
AcLAND, T. D. : "Vaccinia in Man." Allbutt and Rolleston's "System of Medicine," Vol. IL Part I, p. 665. 1912.
CoPEMAN, MoNCKTON : "Pathology of Vaccinia." Allbutt and Rolleston's "System of Medicine," Vol. II, Part 1, p. 746.
Baron, John : "The Life of Edward Jenner, with Illustrations of His Doc- trines and Selections from His Correspondence." Vols. I and II, Henry Colburn, London, 1838.
Vaccination Law of April 8, 1874. German Empire. Published in English. P. Paul, Berlin, 1904.
ScHAMBERG, J. E. : "Vaccination and Its Relation to Animal Experimenta- tion." Defense of Research Pamphlet, No. 1. Am. Med. Ass'n.
McVail, J. C: "Half a Century of Smallpox and Vaccination." Edin-
burgh, 1919,
RABIES
Synonyms. — Hydrophobia; Wasserscheu, Wvt, Tollwut (Germ.an) ; Ijyssa (Greek) ; La Rage (French).
Rabies is an acute, specific, rapidly fatal paralytic infection com- municated from a rabid animal to a susceptible animal, through a wound usually produced by biting. Man always contracts the disease from some lower animal, usually the dog. The infective agent must be in- oculated into the tissues; the virus is harmless when ingested, provided the mucosa is intact. The gastric juice has a pronounced deleterious ef- fect upon the virus. Rabies may be regarded as a wound infection. The specific principle is contained in the saliva of animals suffering with the disease. The infection, therefore, may be conveyed by licking, etc.,
EABTES 39
provided there are fissures or open wounds in the skin. It is also possible to introduce the virus through autopsy accidents and other unusual ways, but commonly it is introduced tlirough wounds produced by the teeth of a rabid animal.
Every mammalian animal is susceptible. Even birds may contract the disease. It is most common in dogs, but it also occurs frequently in wolves, jackals, foxes, and hyenas, liabies in cats is comparatively rare. Cattle, sheep, and goats are infected relatively in about the same degree. It is less common in horses. Swine contract the disease less frequently than other domestic animals. Skunks may contract the dis- ease and sometimes transmit it to man.
Althougli all mammals are susceptible to rabies, it is perpetuated in civilized communities almost exclusively by the domestic dog, only to a small extent by wild animals of the dog family, and occasionally by skunks, cats, etc.
Eabies exists practically all over the world. It has never been in Australia, and has not been known in Denmark, Norway and Sweden for more than fifty years. Rabies had been eradicated from England, but was reintroduced during the World War by dogs carried in flying machines. It is most common in France, Belgium, and Russia, In France, rabies of a virulent type with a short incubation period has spread since the first of the World War. In the United States 111 hu- man deaths were reported in 1908. In the same year there wer« 535 localities in which rabid animals were reported; in 1911 there were 1,381 localities, and 98 deaths in man. In 1890 the United States census reported 143 deaths in 30 states, and in 1900 but 23 deaths. In 1916, 21 deaths were reported from 11 states. In 1919, 45 deaths were reported in the United States.
Eabies is remarkable on account of its high mortality — practically 100" per cent. After symptoms are pronounced recovery rarely, if ever, takes place. Joseph Koch (1910), however, describes an abortive rabies. The disease is peculiar in several other particulars, especially the period of incubation, which is more variable and more prolonged than that of any other acute infection.
Eabies is commonly supposed to prevail only during the hot months, but it is in fact more prevalent in cold weather. Exposure to cold seems to increase its virulence. More dog bites occur from April to September than from October to March in this climate, because dogs run abroad more freely at this season of the year.
Period of Incubation. — From the standpoint of prevention it is for- tunate that the period of incubation of this disease is prolonged. This period varies from 14 days to a year or more. Such prolonged periods of incubation indicate latency. The average period is as follows: Man, 40 days (apt to be shorter in children) ; dogs, 21-40 days; horses, 28-56
40 DISEASES HAVIXG SPECIAL PEOPHYLAXIS
days; cows, 28-56 days; pigs, 14-21 days; goats and sheep, 21-28 days; birds, 14-40 days.
The period of incubation depends largely upon the site of the wound, the relation to the nerve, the amount and virulence of the virus. It requires about 15 days, counting from the last injection, to induce an active immunity to the disease by means of the Pasteur preventive treat- ment. There is, therefore, usually sufficient time, if the case is seen early, to prevent the development of symptoms.
It is probable that the prolonged period of incubation is due in part to the fact that it takes time for the virus to travel along the nerves to the central nervous system, and also to the fact that after the virus reaches the central nervous system, it may remain dormant (latent) until favorable conditions permit multiplication and the production of toxic effects.
Entrance and Exit of the Vims. — The active principle' of rabies occurs principally in the saliva and in the central nervous system. It may be in the saliva at least three days (possibly eight) before the ani- mal shows symptoms (Eoux and Xocard). It is, therefore, sufficient to watch a dog that has bitten a person or another animal for ten days. If no symptoms of rabies appear during this time there is no danger of convej'ing the disease, and the Pasteur prophylactic treatment is unneces- sary.
The virus has been found in the adrenals, the tear glands, the pan- creas, the vitreous humor, the spermatic fluid, the urine, the lymph, the milk, as well as all parts of the central nervous system and the peripheral nerves. It is also found in the spinal and ventricular fluids. It has not been demonstrated in the liver, spleen, blood, or muscles.
The virus enters the system through the broken skin and follows the nerve trunks from the seat of injury to the spinal cord, thence to the medulla and brain. The route corresponds to that of tetanus toxin. The mode of invasion of the virus may explc^in why pain, throbbing, tingling, numbness and other nervous disturbances are the first symp- toms to occur in parts of the body that have received the virus. It also partly explains the variable period of incubation, which is shorter in wounds of the face than wounds of the extremities. It also explains why the disease is more liable to occur when the wounds are in parts of the body with a rich nerve supply. I have experimental evidence (un- published) that indicates that the virus readily enters the nerve endings in the skin.
iS^oguchi -^ announces that he has succeeded in growing the virus, which appears in cultures as granular and pleomorphic chromatcid bod- ies, some of which are surroimded with membranes. Williams -® and
=^Xoguchi, Jour. Exp. Med.. 1913, XVII, 29.
^Williams, Anna Wessel; Jour. A. M. A., 1913, LXI, 17, p. 1509.
RABIES 41
Moon ^^ believe they have evidence of growtli in Ijrain tissue, having pro- duced rabies in animals in the fiftli gont'ration or transfer of such ''cul- tures.*'
The Relative Danger of Bites. — Wolf bites are most dangerous on account of the savage character of the wound, and the virulence of the virus. Cat bites come next, and then dog bites. The relative danger of bites of other animals is as follows: foxes, jackals, horses, asses, cattle, sheep, pig?. There is no authentic instance of the transmission of the disease by the bite of man, though this may be possible. The bites of horses and other herbivora are less dangerous because their blunt teeth usually cause contused wounds without breaking the skin.
Bites on exposed surfaces are more dangerous than through the cloth- ing, because the saliva is wiped from the teeth and little or none enters the wound. Long-haired dogs and sheep often escape infection for the same reason. Bites upon the face are most apt to be followed by rabies.
Not every person bitten by a mad animal develops rabies. Leblanc's figures are 16.6 per cent. The statistics are difficult to analyze, and it is almost impossible now to collect' sufficient data. According to the most reliable figures, it would seem that rabies develops in not less than one person in ten bitten by mad dogs, and not receiving the Pasteur treatment. Paltauf places the figures at 6 to 9 per cent. From 15 to 20 per cent, is a moderate estimate of the death rate for all persons bit- ten by rabid animals. 8ee also page 49.
Viability. — The virus of rabies in the spinal cord of rabbits dies in about li days when dried at 20°-22° C. if protected from putrefaction and light. Spread in thin layers, it dies in -1 or 5 days, and exposed to the sunlight in 40 hours. It is quite resistant to putrefaction. In a decomposed carcass it may be recovered by placing some of the central nervous system in glycerin. The glycerin destroys most of the con- taminating bacteria, but preserves the virus. Rabic virus is completely destroyed at 50° C. in one hour, and at 60° C. in 30 minutes. It is not injured by extreme cold.
Harris found the virus to be very resistant to dryness at low tem- peratures. Rabic virus in central nervous tissue is very resistant to ordinary germicides. Sawtschence ^° found that.it requires from five to seven days to destroy the fixed virus in 5 per cent, phenol, and that it is not destroyed by 0.5 per cent, phenol in 20 days. Other filterable viruses, notably variola and vaccinia, also show unusual resistance to phenols and cresols. Semple ^'^ found that the emulsion of fixed virus which resists the action of 1 per cent, phenol at room temperature for
=»Moon, Jour. Infect. Dis., 1913. XIII. 232. »> Sawtschence, W., Ann. de VInst. Pasteur, 1911. XXI, p. 492. '^ Semple, "Sci. Mem. by OflBcers of Med. and San. Depts.," Gov. Ind., X. S., No. 44.
43 DISEASES HAVING SPECIAL PKOPHYLAXIS
several da3^Sj succumbs at 24 hours at 37° C. x\ccording to Gumming ^^ 1 per cent, phenol does not destroy the virus in 6 hours, while 2 per cent. solution kills it in less than 24 hours. On the other hand, most of the aldehj'd compounds are very active in destroying the infectivity of the fixed virus. A 0.5 per cent, solution of salicylaldehyd, benzaldehyd, or furfurol destroys the virus in less than 3 hours. The specific disinfect- ing action of formaldehyd is shown by the fact that the virus is destroyed when exposed for two hours to 0.08 per cent, solution. This indicates that formalin may be a useful substance to treat dog bites, although experiments have shown that it is not as dependable as nitric acid. Bichlorid of mercury, 1-1,000, for 1 hour, or a . saturated solution of iodin in water, completely destroys the virulence, and Wyrsykowski has shown that gastric juice has a pronounced deleterious effect upon the virus.
PROPHYLAXIS
The prevention of rabies is considered under three heads: (1) Treatment of the wounds; (2) the Pasteur prophylactic treatment, and (3) the control of the disease in dogs by muzzling and quarantine.
The cauterization of the wound and the Pasteur prophylactic treat- ment are efficient preventive measures for the individual, but they are not the true and best methods of controlling and preventing rabies. The disease may be avoided, even exterminated, by an intelligent system of muzzling and quarantining of dogs. A high tax on dogs and leashing are only restrictive measures. In England, when the dogs were muzzled, rabies diminished. The law was repealed, owing to misplaced sympathy for the dog, and rabies promptly increased. The law was again enforced, and in about two years the disease disappeared (see Fig. 10). A strict quarantine of six months was maintained against dogs en- tering England, but this was broken by the war and rabies reappeared in England in 1918.^^ Consistent muzzling of all dogs for two years will practically exterminate rabies. In Australia there are few carniv- orous animals, mostly marsupials; there rabies does not exist, for it has been kept out owing to early and effective quarantine measures. ]S[orway, Sweden, and Denmark also obtained good results and the same can be done in other peninsular regions.
Prophylactic measures necessary to control the dog question are: the destruction of ownerless dogs ; license fee and tag for all dogs ; own- ers to be legally responsible for damage infiicted by their dogs; educa- tion of the dog-owning public concerning the spread of communicable diseases, especially rabies ; compulsory reporting of all cases or suspected cases of rabies. Further special measures advocated are: muzzling;
^^Jour. Infect. Dis., XIV, 1, January, 1914, p. 33. ^Br. Med. Jour., March 22. 1919, 350, 1.
RABIES
43
restraint ^vitIl chains, leash, etc.; observation in quarantine, or killing of all animals hitton by dogs; disinfection, etc. ^*
THE LOCAL TREATMENT OF THE WOUND
Wounds produced by the bite of an animal in which there is any suspicion of rabies should at once be cauterized with "fuming" or strong nitric acid.^'^ The acid is best applied with a glass rod very thoroughly
Fig. 10. — Chart Showing Relation of Enforcement of Muzzling Law to Prevalence of Rabies in Great Britain (the figures in the cross-hatching indicate the number of persons who died of rabies in England and Wales. The ordinates represent cases in dogs). (Straus and Frothingham. )
to all the parts of the wound, care being taken that pockets and recesses do not escape. Thorough cauterization at once reduces the danger of wound complications, and experience demonstrates that wounds so treated at once are pu'actically never followed by rabies. Marie obtained conflicting results with local treatment in experimental rabies ; Cabot ^^ obtained the best results with nitric acid, and was able to save the lives
** In addition to rabies, dogs are responsible for other infections in man, such as hydatids, tapeworms (especially in children), round worms, tongue worms, and also fleas and ticks which transfer from the dog to man and which may in this way transmit diseases and parasites. In animals, dogs are re- sponsible for gid in live stock and cysticerci in sheep, reindeer and live stock.
^' Sp. gr. over 1.48.
^' Medical News, March, 1899.
44 DISEASES HAVING SPECIAL PROPHYLAXIS
of 91 per cent, of guinea-pigs by cauterization with nitric acid at the end of 34 hours; Poor ^^ saved 45 per cent., at the "end of 32 hours. In the absence of nitric acid, formalin or the actual cautery may be used, but they have inferior prophylactic value. Strong germicides, such as carbolic acid, are not reliable. Nitrate of silver is valueless. In any wound produced by the bite of an animal cauterize with nitric acid unless sure that the animal is not mad.
Experiments made in my laboratory indicate that no substance takes the place of nitric acid, and further emphasizes the importance of, cauterizing all portions of the wound, especially the edges of the skin.
It has been shown that the virus may remain alive and virulent in the scar for a long time, and it has become a question whether patients seen after the wound has healed should not have the scar excised and the wound cauterized with nitric acid ; this, however, is not the practice.
THE PASTEUR PROPHYLACTIC TREATMENT
This method of prophylaxis was announced December 6, 1883, by Pasteur, at the International Congress at Copenhagen, and on February 24, 1884, he laid before the French Academy the details of his experi- ments and results. The next year Pasteur, with the help of Eoux and Chamberland, worked out the details of the method now in general use.
The principle of the treatment consists in producing an active im- munity by means of an attenuated virus. The virus is attenuated by drying. The fixed virus contained in the spinal cord of rabbits dead of hydrophobia is the material used, for subcutaneous injection.
Street Virus and Fixed Virus. — The distinction between fixed and street virus is of fundamental importance in reference to the question of immunity. Street virus is obtained from mad dogs naturally in- fected. When this virus is inoculated into a rabbit, it reproduces the disease after a period of incubation of from 14 to 21 days or more. This street virus may then be conveyed from rabbit to rabbit through a number of transfers. In the passage from rabbit to rabbit the virus becomes more virulent for rabbits. The period of incubation is pro- gressively shortened, until finally the rabbits invariably sicken on the sixth or seventh day and die on the ninth or tenth. When the virus has reached this degree of virulence for rabbits, it is said to be "fixed," for the reason that its potency remains constant. In its passage through rabbits the modification from street virus to fixed virus is gradual. It is important to note that fixed virus, which has attained a high degree of virulence for rabbits, has lost much of its virulence for
^'Collected Studies, Research Lab., Dept. of Health, City of N. Y., VI, 1911, p. 25.
T^ABTES 45
dogs, and seems to bo aviruli'iit fur man when introduced into the sub- cutaneous t issue. •''^^
Ferran in 1888 treated 85 persons for dog bites by injecting the fresh fixed virus subcutaneously, without ill effects. Wysokowiez in 1902 injected 70 persons intravenously without an accident. In in- stitutes using the method of Hoyges, many persons have received dilu- tions of an emulsion of the fresh pons and medulla. Xitsch. Proescher and others injected large amounts of fresh fixed virus subcutaneously without producing symptoms. Proescher, in fact, injected himself with the entire brain and medulla of a rabbit; and another entire brain into a volunteer. Xo ill eifects of any kind were noted. The virus used was shown to be virulent when a small amount of it was introduced under the dura of a rabbit. It is indeed quite difficult to give rabies to animals experimentally by subcutaneous injection. Marx tested the fresh fixed virus upon monkeys in large doses, with negative results. The evidence points clearly to the fact that the fixed virus of rabbits does not produce rabies in man when introduced into the subcutaneous tissue.
Preparation of the Virus. — Eabbits are injected under the dura mater with a few drops of an emulsion of fresh fixed virus obtained from the pons or medulla of another rabbit dead of hydrophobia. Strict aseptic precautions are necessary in order to keep out other infections. The rabbit should begin to show symptoms on the six:th or seventh day, and die on the ninth or tenth. Usually the rabbit is not allowed to die, but is chloroformed on the last day in order to avoid terminal infections and unnecessary suffering. The spinal cord is removed and hung in a bottle containing potassium hydroxid. These bottles are kept in the dark at a temperature of 23° C. Under these conditions the cord grad- ually desiccates, and at the same time the virulence of the virus di- minishes, until the fourteenth day, when it is no longer infective. This is why Pasteur started the treatment with a cord fourteen days old. In fact, the virus dies long before the fourteenth day — five-day old cord usually fails to infect.
About one-half a centimeter of the cord constitutes a dose. This is
ground in about 2.5 c. c. of sterile salt solution so as to produce a
uniform emulsion, which is injected into the subcutaneous tissue of the
abdominal wall. In many institutes the small segments cut each day
from the drying cord are placed in pure glycerin. The virulence of the
cord in glycerin is not altered for at least 30 days, if kept in the dark
and at 15° C. This method, introduced by Calmette^^ in 1891, based
upon observation made by Roux in 1887,^° is very convenient, especially
=^N. Y. Med. Jour., Oct. 9, 1909, also Arch, of Int. Med., Sept., 1911, VIII, 3, p. 353.
^Ann. de VInsi. Pasteur, Paris, 1801, Vol. V, p. 633. *^ Ann. de VInst. Pasteur, Paris, 1887, Vol. I, p. 87.
46
DISEASES HAVING SPECIAL PROPHYLAXIS
where comparatively few patients are treated. Glycerin has the added advantage of destroying infections due to non-spore-hearing hacteria that may be present.
As a further precaution, bacteriologic examinations are made of parts of the spinal cord in order to insure the absence of bacteria, and the rabbit is carefully autopsied as a guarantee that no other disease is present.
The Scheme of Treatment. — The scheme of treatment advocated by Pasteur and still used at I'lnstitut Pasteur in Paris and many other places is shown in the following table:
PASTEUR PROPHYLACTIC TREATMENT — RECOMMENDED BY PASTEUR
|
Mild Treatment |
Intensive Treatment |
||||
|
Amount of In- |
Amount of In- |
||||
|
Day |
Age of |
jected Emulsion |
Day |
Age of |
jected Emulsion |
|
of |
the Dried |
1-cm. of Cord to |
of |
the Dried |
1 cm. of Cord to |
|
Treatment |
Cord |
5 c. c. Salt Solu- tion |
Treatment |
Cord |
5 c. c. Salt Solu- tion |
|
ri4 Days |
3 c. c. |
||||
|
1 |
f 14 Days 113 |
3 c. c. |
1 |
J 13 |
3 |
|
3 |
1 12 |
3 |
|||
|
111 |
3 |
||||
|
flO |
3 |
||||
|
2 |
ill |
3 3 |
2 |
{f |
3 3 3 |
|
3 |
{'I |
3 3 |
3 |
f 6 \ 6 |
2 2 |
|
4 |
i' |
3 3 |
4 |
5 |
2 |
|
5 |
it |
2 2 |
5 |
5 |
2 |
|
6 |
5 |
2 |
6 |
4 |
2 |
|
7 |
5 |
2 |
7 |
3 |
1 |
|
8 |
4 |
2 |
8 |
4 |
2 |
|
9 |
3 |
1 |
9 |
3 |
1 |
|
10 |
5 |
2 |
10 |
5 |
2 |
|
11 |
5 |
2 |
11 |
5 |
2 |
|
12 |
4 |
2 |
12 |
4 |
2 |
|
13 |
4 |
2 |
13 |
4 |
2 |
|
14 |
3 |
2 |
14 |
3 |
2 |
|
15 |
3 |
2 |
15 |
3 |
2 |
|
16 |
5 |
2 |
16 |
5 |
2 |
|
17 |
4 |
2 |
17 |
4 |
2 |
|
18 |
3 |
2 |
18 |
3 |
2 |
|
19 |
5 |
2 |
|||
|
20 |
4 |
2 |
|||
|
21 |
3 |
2 |
Some Pasteur institutes now use a modified treatment, starting with an 8-day instead of a 14-day-old cord, which is exemplified in the scheme used at the Hygienic Laboratory, Public Health Service. See table on the following page.
The tendency is to hasten the immunity by using only the intensive treatment for all cases, also to start with fresher cord, some using 4- day-old cord for the initial injection. Intensive treatment should al- ways be given for wounds of the face, head, hand and other exposed parts of the body ; for multiple wounds ; severe wounds ; or for wolf, fox, cat and skunk bites.
RABIES
PASTEUR PROPHYLACTIC TREATMENT— HYGIENIC LABORATORY WASHINGTON, D. C.
47
|
Amount of Emulsion 1 c. c. of Cord to 5 c. c. Salt |
||||
|
Day |
Age of the Dried Cord |
Solution |
||
|
Adult |
5 to 10 Years |
1 to 5 Years |
||
|
1 |
6—6* |
2.5 c. c. |
2.5 c. c. |
2.5 c. c. |
|
2 |
5 — 5* |
2.5 |
2.5 |
2.5 |
|
3 |
4 — 4* |
2.5 |
2.5 |
2.5 |
|
4 |
3 |
2.5 |
2.5 |
2.0 |
|
5 |
3 |
2.5 |
2.5 |
2.0 |
|
fi |
2 |
2.5 |
2.0 |
1.5 |
|
7 |
2 |
2.5 |
2.5 |
2.0 |
|
8' |
1 |
2.5 |
1.5 |
1.0 |
|
9 |
5 |
2.5 |
2.5 |
2.5 |
|
10 |
4 |
2.5 |
2.5 |
2.5 |
|
11 |
4 |
2.5 |
2.5 |
2.5 |
|
12 |
3 |
2.5 |
2.5 |
2.0 |
|
13 |
3 |
2.5 |
2.5 |
2.0 |
|
14 |
2 |
2.5 |
2.5 |
2.0 |
|
15 |
2 |
2.5 |
2.5 |
2.0 |
|
16 |
4 |
2.5 |
2.5 |
2.5 |
|
17 |
3 |
2.5 |
2.5 |
2.5 |
|
18 |
2 |
2.5 |
2.5 |
2.0 |
|
19 |
3 |
2.5 |
2.5 |
2.5 |
|
20 |
2 |
2.5 |
2.5 |
2.5 |
|
21 |
X |
2.5 |
2.5 |
2.5 |
* Double dose.
The scheme of Pasteur has been further modified in various ways, depending upon the method used to attenuate the virus. Thus Pasteur attenuated the virus by drying; Babes by heating; Frantzer by tlie use of bile; Tizzoni and Cattani attenuated the virus in gastric juice. Hog- yes used fresh material in a diluted suspension; Ferran fresh material and in increasing doses. Gumming altered the virus by dialysis. Har- ris dried the fresh virus at low temperature, which is used in diluted sus- pension. Other methods have been used to attenuate the virus, such as glycerin, carbolic acid, mechanical disintegration, and, lastly, antirabic serum. Ferran in Barcelona, Proescher in Pittsburgh, and others in- ject patients with the unaltered, fresh, fixed virus. The advantages of using the virus as fresh and strong as possible are that an active im- munity is produced more quickly, and this is of considerable importance in wounds of the face; also in wolf and cat bites, which frequently have a short period of incubation. Further, fewer injections of the fresh virus are necessary to produce an immunity, and this shortens and sim- plifies the treatment.
Harris *^ has shown that rabic material may be completely desiccated without destruction of virulence, provided the dehydration takes place at a low temperature. The lower the temperature the greater will be the amount of virulence preserved. Virus so desiccated contains per weight as much infectivity as the fresh virus. The virus thus dried is so stable that it may be standardized, permitting an accuracy of dosage hitherto impossible. The unit is the smallest amount which, Avhen injected in- tracerebrally into a full-grown rabbit, will produce paresis on the
*^Jour. of Infect. Dis., May, 1912, X, 3, pp. 369-377.
48 DISEASES HAVING SPECIAL PROPHYLAXIS
seventh day. For slight wounds Harris gives seven injections, but for severe injuries he gives two injections a day for twelve to fourteen days.
Treatment at a distance from a Pasteur institute is now practical by sending a piece of cord in glycerin; or the emulsion in glycerin, in a thermos bottle; or the dry material in accordance with Harris' method.
Care During the Treatment. — During the treatment the patient may go about his usual business. It is not necessary to stay in bed. The patient should, however, avoid fatigue, cold, emotional stress, trauma, and alcohol. It has been shown that these are important pre- disposing factors to the disease. It was found that customs' officers re- turning to the Siberian borders after prophylactic treatment for wolf bites showed an unusual mortality, which seemed to de due to exposure to cold. The disease has been observed to be brought on after a cold bath, falling into the water, and similar depressing influences.
Complications of the Treatment. — The Pasteur prophylactic treat- ment may be complicated, by (1) local reactions or (2). paralysis.
Local reactions at the site of the wound are) usually trivial. Abscesses almost never occur. The local reactions consist of redness and indura- tion. It is not necessarily the last injection, but rather the site of some previous injection that flares up, but soon subsides without further trouble. This occurrence increases with the progress of the treatment; it is most frequent in the second week. As the treatment involves the introduction of a large quantity of foreign proteins into the body, it is probable that these reactions represent a phase of hypersusceptibility. See Anaphylaxis.
Paralysis. — Paralysis occurs occasionally and may be fatal. This complication seems to be a mild or modified type of rabies, but there is doubt concerning its cause. There is evidence that it may be due to infection with the fixed virus or possibly to toxin — or both. Serious paralysis is a rare complication; it doubtless occurs in mild form more often than is known. It affects adults chiefly, young children almost never. Simon collected data up to and including 1911, showing the occurrences of 100 instances of paralysis among 317,774 persons treated. In this series there were 19 deaths. The incidence of paralysis seems to vary with different methods of antirabic treatment.*^
In a case treated at the Hygienic Laboratory the paralysis came on 18 days after treatment, and was transient. H. E. Hasseltine *^ reports two cases of paralysis following antirabic treatment, with one death. The New York Pasteur Institute reports a death from "ascending paralysis," which came on four days after the treatment. W. A. Jones ** reported two cases with recovery. In 1905 Eemlinger, head of the Constanti-
**The subject is brought up to date in Fiedler's article in the Journal of the Amerioan Medical Assooiation, June 3, 1916, LXVI, p. 23.
« Public Health Report, July 30, 1915, Vol. XXX, No. 31, p. 2227. '*Jour. A. M, A., Nov. 13, 1909, p. 1626.
KABIES 49
nople Institute for Eabies, reported 40 cases of paralysis; Babes had 8 cases of paralysis (all mild) in (),5"i5 treatments; Miiller found 16 cases in the literature, and had two of his own ; Panpoukis, three cases ; Jones, 2. Mejio *'' reported 19,800 cases treated in the Pasteur institute, Buenos Aires, of whom 24 developed paralysis, with 4 deaths. One instance was a child of six, apparently healthy a month after the Pasteur treatment. He then had a fall from a hammock; the next day his legs were para- lyzed; the paralysis proved of the ascending type, fatal in two weeks.
The Immunity. — Duration. — The immunity appears two weeks after the treatment and lasts a varying period of time, depending upon the individual — at least for several years. In this respect it does not differ from other instances of acquired immunity. The Pasteur prophylactic may be repeated in persons bitten a second time. The lower animals may also be protected. The fact that the immunity appears on the fifteenth day after the last treatment was discovered by Pasteur as a re- sult of animal experimentation. The statistics of the Pasteur Institute, giving the mortality from rabies in persons following the prophylactic treatment, exclude instances in which the disease develops within fifteen days after the last prophylactic injection.
Nature. — The nature of the immunity is not clear. It certainly is not due to an antitoxin. Immune bodies are demonstrable in the blood twenty days after the last injection. The activity of the virus can be neutralized by mixing it in vitro with the blood serum of an im- munized animal. This neutralization is generally considered to be mi- crobicidal or lytic in nature.
Degree. — The degree of the immunity also varies, as is evidenced by the fact that a certain small percentage of the persons treated die of rabies.
The Results of the Treatment. — Statistics giving the results of the treatment are somewhat difficult to analyze, as many factors are unob- tainable. Patients should be kept under observation at least a year. Exceptional cases occur one year following exposure. Cases that occur within fifteen days after the treatment are excluded from the French statistics, for reasons that have already been stated. The figures on this basis show a mortality of less than 0.5 per cent. Better results are being obtained from year to year.
The table on the following page gives the general results at ITnstitut Pasteur, Paris, since beginning the treatment.
When we compare these figures with the fact that from 6 to 10 per cent, and sometimes 16.6 per cent, of all persons bitten by rabid dogs die of rabies, the prophylactic value of the Pasteur treatment is evident.
Faber found 27 deaths out of 339 persons bitten by mad dogs; Kur- rimoto, 17 per cent, in Nagasaki; Babes, 15 per cent, of 995 in Hun-
" Semana Medica, Buenos Aires^ XXIV, No. I, p. 10.
50
DISEASES HAVING SPECIAL PROPHYLAXIS
RESULTS OF TREATMENT AT L'INSTITUT PASTEUR, PARIS
|
Year |
Persons treated |
Deaths |
Mortality |
Year |
Persons treated |
Deaths |
Mortality |
|
1886 |
2,671 |
25 |
0.94% |
1903 |
628 |
2 |
0.32% |
|
1887 |
1,770 |
14 |
0.79 |
1904 |
755 |
3 |
0.39 |
|
1888 |
1,622 |
9 |
0.55 |
1905 |
727 |
3 |
0.41 |
|
1889 |
1,830 |
7 |
0.38 |
1906 |
772 |
1 |
0.13 |
|
1890 |
1,540 |
5 |
0.32 |
1907 |
786 |
3 |
0.38. |
|
1891 |
1,559 |
4 |
0.25 |
1908 |
524 |
1 |
0.19 |
|
1892 |
1,790 |
4 |
0.22 |
1909 |
467 |
1 |
0.21 |
|
1893 |
1,648 |
6 |
0.36 |
1910 |
401 |
0 |
0.00 |
|
1894 |
1,387 |
7 |
0.50 |
1911 |
341 |
1 |
0.29 |
|
1895 |
1,520 |
5 |
0.38 |
1912 |
395 |
0 |
0.00 |
|
1896 |
1,308 |
4 |
0.30 |
1913 |
330 |
0 |
0.00 |
|
1897 |
1,521 |
6 |
0.39 |
1914 |
373 |
0 |
0.00 |
|
1898 |
1,465 |
3 |
0.20 |
1915 |
654 |
1 |
0.15 |
|
1899 |
1,614 |
4 |
0.25 |
1916" |
1,388 |
3 |
0.21 |
|
1900 |
1,420 |
4 |
0.28 |
1917 |
1.543 |
4 |
0.26 |
|
1901 |
1,321 |
5 |
0.38' |
1918 |
1,803 |
3 |
0.16 |
|
1902 |
1,005 |
2 |
0.18 |
1919 |
1,813 |
" |
0.16 |
gary; Horsley's figures are 15 per cent. Some series of cases give a much higher mortality. Thus, of 855 persons bitten by mad dogs, col- lected by Tardieu, Thamehayn, and Bouley, 399 ended in death, or 46.6 per cent. In another series of cases given by Bouley, out of 266 per- sons bitten by mad dogs, 152 died of hydrophobia. But of these 120 were bitten on the face and hands, the greater danger of which has been mentioned. The mortality resulting from bites of wolves is placed by Babes at from 60 to 80 per cent.
Contraindications, — There are no known contraindications to the treatment. All ages and conditions should be treated if exposed. Ap- parently no harm is done pregnant women. I have injected patients having malaria without trouble following. The treatment may be con- tinued in patients having colds, fevers, and other ailments without no- ticeable harm.
When to Give the Pasteur Prophylactic. — It is sometimes difficult to decide whether the Pasteur prophylactic treatment should or should not be given. Treatment causes sufficient personal inconvenience, not to speak of the danger (however slight) of paralysis, to avoid advising it if unnecessary. In many cases it is impossible to discover whether the dog that inflicted the bite is mad or not. The rule in cases of doubtful exposure is to advise the treatment.
Persons who apply for treatment of dogbites fall into one of the five following categories with reference to the Pasteur prophylactic :
( 1 ) The dog is mad or shows suspicious symptoms : In this case, begin treatment at once.
(2) The dog is not mad: Observe it carefully for ten days, and if no symptoms develop, there is no danger of rabies in the person bitten. The treatment is therefore unnecessary. (The dog may nevertheless develop rabies after ten days and if it has been bitten by another dog should be kept in quarantine for six months.)
EABIES 51
(3) The dog is not identified: This is a common occurrence, es- pecially with children. The rule in such cases is to advise the Pasteur prophylactic treatment, except in places known to be free of rabies.
(4) Exposure to saliva: Persons not infrequently apply for ad- vice giving the following history : They have not been bitten, but they have been licked on the hands and face by a dog that subsequently was discovered to have the disease. Persons are sometimes similarly exposed by washing the mouth of a rabid horse. In tliese cases the important question is whether there were fissures or abrasions in the skin at the time. There may be little wounds in the skin not evident to the naked eye. It is possible to infect animals by rubbing the virus on the shaved skin. The rule is therefore to advise the protection which the treat- ment affords in persons thus exposed.
(5) In psychoneurotic patients with a distressing phobia of rabies, it may atford comfort to give a mild course of treatment as much for its psychotherapeutic effect as for specific immunity.
The Dog. — In all cases it is important to know whether the dog is mad or not. If the dog can be found and kept under observation for 10 days and no symptoms appear, the Pasteur treatment is not necessary. Animals killed early in the course of rahies may fail to show the mi- croscopic evidence of the disease, thus causing an indefinite delay in diagnosis awaiting inoculation tests. Dogs that have bitten persons should not be summarily killed, but should be apprehended and turned over to the proper authority; if killed, the head should be sent to the nearest diagnostic laboratory. Should the dog develop symptoms, the question of diagnosis is all-important.
Diagnosis of Rabies in Dogs. — The diagnosis of rabies in dogs may be made in four ways: (1) from the symptoms; (2) from the presence of Negri bodies in the central nervous system; (3) from the lesions in the- peripheral ganglia, and (4) by animal inoculations.
1. The symptoms may be very suggestive, but a diagnosis must al- ways rest upon the pathological lesions and the inoculation tests. The course of the disease may be divided into three stages: (a) a premoni- tory stage, (b) a stage of excitement, and (c) a paralytic stage. The first two stages may be absent or transient. All rabid animals invariably become paralyzed before they die. In dogs the first symptom consists solely in a change in the disposition of the animal. He is easily excited, but does not show a tendency to bite. Soon the restlessness becomes more marked, and the animal may become furious and even show signs of delirium. The dog does not fear water, as is commonly supposed, but rushes about attacking every object in his way. Dogs suffering from furious rabies have a tendency to run long distances (25 miles or more), often biting and inoculating large numbers- of other animals and persons en route. Very soon paralysis sets in, commencing in the hind legs, and
52 DISEASES HAVING SPECIAL PROPHYLAXIS
finally becomes general. The course of the disease is always rapid, averaging from 4 to 5 days, rarely exceeding 10 days. When the stage of excitement is brief or absent, the disease is known as dumb rabies.
2. There is a difiEerence of opinion concerning the significance of the Negri bodies {Neurorrhydes hydrophobiae) , which, however, are very constant in rabies and peculiar to it. If Negri bodies are found in the dog, the Pasteur treatment should be started at once. The absence of Negri bodies, however, does not necessarily mean the absence of rabies. These bodies are sometimes difficult to find, or may not be present in the parts of the central nervous system which are examined. Negri bodies are found especially in the horn of Ammon and the cerebellum; they are 1 to 23 micra in diameter; usually round or oval; strongly eosino- philic; occur within and without the nerve cells; and sometimes con- tain a nucleus (?). Owing to their resemblance to red blood cells, the finding of Negri bodies iHthin the cells is the safest criterion. The diagnosis may thus be established in about 90 per cent, of cases.
Negri bodies for diagnostic purposes are best demonstrated by im- pression preparations of Amnion's horn and cerebellum, stained accord- ing to Van Giesen as recommended by Frothingham or stained by Bond's modification of the Mann stain. Impression preparations are made by gently pressing a microscopic slide upon the cut surface of Ammon's horn and the cerebellum and lifting with a quick movement. Care should be taken to obtain thin uniform impressions because thick impressions do not show differential staining for Negri bodies. Pieces of the Ammon's horn and the cerebellum selected for impressions should be from four to six millimeters thick. Three or four impressions to a single slide should be made from each piece of the Ammon's horn and ccreljellum. Four or five pieces of each Ammon's horn and the same number from the cerebellum are sufficient. The impression preparations obtained in this way show the characteristic arrangement of the cells of the hippocampus and of the cerebellum and rarely fail to contain the Negri bodies in infected material. When the brain is badly mutilated or decomposed, impressions taken from any of the available material containing gray matter will frequently show the Negri bodies if infected.
To stain impression preparations as recommended by Frothingham the following slightly modified procedure is given: (1) Fix before the impression dries in methyl alcohol for five minutes; (2) stain at room temperature with Van Giesen, while still moist with alcohol, for eight to ten minutes; (3) wash thirty seconds with running tap water; (4) blot with filter paper. The Van Giesen stain is made as follows: Tap water 20 c. c. to 50 c. c; saturated alcoholic fuchsin (f. Bac. Grubler) 1 drop; saturated aqueous solution methylene blue (f. Bac. Koch Grubler) one to ten drops. The amount of tap water and the
RABIES 53
amount of methylene bine required for irood differentiation vary with different stock solutions of the stains. This stain changes little in three to four days.
To stain by Bond's mudilication of the Mann stain proceed as fol- lows: (1) Fix before the impression dries in methyl alcohol five to six minutes; (2) wash thirty seconds with running tap water; (3) stain for four to five minutes Avith a mixture consisting of 1.0 c. c. of 1 per cent, aqueous eosin (Eosin W. gelbl. Grubler), 0.7 c. c. to 1.0 e. c. of 1 per cent, aqueous methyl blue (Grubler) and 6.0 c. c. of distilled water; (4) wash with running tap water for thirty seconds; (5) blot with filter paper; (6) dehydrate with absolute alcohol; (7) clear with a mixture consisting of one part of xylol and two parts of aniline oil; (8) Avash with xylol: (9) mount in balsam. The ^lann stain should be freshly prepared each time it is used. In practice it is better to stain by both methods because each has its advantages and disadvantages. The Mann's stain gives definite Xegri bodies but the differential staining be- tween the red blood corpuscles and ]Sregri bodies is not always clear. "With the Frothingham method Xegri bodies can hardly be mistaken for anything else but the stain itself may be capricious in action and shows relatively fewer Xegri bodies.
3. The lesions of Van Gehuchten and Xelis, described in 1900, are the most characteristic anatomical changes. These lesions are found late in the disease in the peripheral ganglia of the cerebrospinal and SA'mpathetic systems, especially in the plexiform ganglia of the pneumo- gastric nerve, and the Gasserian ganglia. The normal nerve cells of these ganglia lie in a capsule lined with a single layer of endothelial cells. In rabies these endothelial cells proliferate and the nerve cells may be partly or entirely destroyed and replaced by diverse cells as- sociated with chronic inflammatory processes. In addition, lymphatic infiltration also occurs about the sheaths surrounding the individual nerve cells. Either the proliferative or infiltrative changes may pre- dominate. In order to find these lesions, it is necessary to fix the ganglia in Zenker's fluid and to stain the sections by the eosin-methylene blue method. This method of diagnosis is available in only a small per- centage of cases.
4. The final diagnosis of rabies rests upon animal experimentation. A small quantity of an emulsion of the medulla or pons of the suspected animal is placed under the dura mater of a rabbit or guinea-pig. The diagnosis by this method, however, requires so much time (on account of the long period of incubation of the disease) that it is of no practical value in deciding whether or not the Pasteur prophylactic treatment should be given, but in any critical case the positive evidence furnished by animal experimentation is incontrovertible.
If the inoculated rabbit shows no symptoms in one month, and Xegri
54 DISEASES HAVING SPECIAL PEOPHYLAXIS
bodies were not seen in the specimen, then a negative diagnosis may be given, although it is customary to observe the animal for six months.
REFERHNCES
Pasteur, Chamberland, Koux and Thuillier: "Sur la Rage," Compi. rend, de I'Acad. de Sci., 1881, 92, p. 1555.
Pasteur, Chamberland and Roux: "iSTouvelle Communication sur la Rage," Compt rend, de VAcad. de Sci., 1884, 98, p. 457; "Sur la Rage," Compt. rend, de VAcad. de Sci., 1884, 98, p. 1229.
Pasteur: "Methode pour Prevenir la Rage apres Morsure," Compt. rend, de I'Acad. de Sci., 1885, 101, p. 765; "Resultats de TApplication de la Methode pour Prevenir la Rage apres Morsure," Compt. rend, de I'Acad. de Sci., 1886, 102, p. 459; "Note Complementaire sur les Resultats de I'Application de la Methode de Prophylaxie de la Rage apres Morsure," Compt. rend, de I'Acad. de Sci., 1886, 102, p. 835; "Xouvelle Communi- cation sur la Rage," Compt. rend, de I'Acad. de Sci., 1886, 103, p. 777; "Lettre sur la Rage," Ann. de I'Inst. Pasteur, 1887, 1, p. 1; "Sur la Methode de Prophylaxie de la Rage apres Morsure," Compt. rend, de I'Acad. de Sci., 1889, 108, p. 1228.
Babes, Victor: "Traite de la Rage." Paris, Bailliere et Fils, 1912. A comprehensive monograph. Contains a good historical account of the story of Pasteur's discovery, with original references.
Stimsox, a. M. : "Facts and Problems of Rabies." Hygienic Laboratory Bulletin No. 65, June, 1910. Contains a selected bibliography. More comprehensive bibliographies will be found in :
Heller: Schutzimpfung gegen Lyssa, 1906.
Hogyes: "Lyssa" in Nothnagels Spez. Path. u. Therap., Wien, 1897.
Marie : L' etude experimentale de la rage. Encyclop. scient., 1909.
Marx, E. : Kolle u. Wassermanns Handh. d. path. Mikroorg., 1904, 4, Bd., 2. TL, 1264.
VENEREAL DISEASES*^
As a danger to the public health, as a peril to the family, and as a menace to the vitality, health, and physical progress of the race, the venereal diseases are justly regarded as the greatest of modern plagues, and their prophylaxis the most pressing problem of preventive medicine that confronts us at the present day.
Xo serious attempt was made by the sanitary authorities of any of our great cities to deal with this problem until Xew York City in
*' Objection has been made to the stigma implied in the term venereal dis- eases, for these infections are not always transmitted in venery and are often contracted innocently. Syphilis and gonorrhea, however, are unlike other com- municable diseases in that they do involve a moral principle. Gonorrhea or syphilis contracted innocently is usually only one remove from promiscuity.
Only one venereal disease among the lower animals is known, — dourine, a syphilis of horses caused by a trypanosome.
VENEREAL DISEASES 55
1012 *'' determined to treat the venereal diseases as any other higlily communieablo and prevcntabU^ infection, dealin<i purely with tiie sani- tary features of the problem from a public health standpoint, ignoring the social and moral phases. The opposition to such activity is slowly being broken down. Progress against the venereal diseases is a repeti- tion of the warfare along other lines of sanitation and hygiene. It is the history of a continuous struggle carried on in the name of law, religion, personal rights, or expediency. Although the dilliculties in this case are much greater thrn in any other group of diseases, an intelligent and persistent campaign must end in a long-delayed success.
Biggs states that in 1912 at least 800,000 people, or more than one- fifth of the adult population of New York City, have, or have had, some venereal disease, and that in a large percentage of these persons the disease is still active. The number of new infections occurring each year probably exceeds that of all other notifiable diseases combined. In view of such figures the magnitude and the importance of the problem of administrative control, as applied to these diseases, become clearly apparent.
The venereal diseases are a constant menace to the clean living public as well as to the licentious. The history of preventive medicine can present no greater tragedy than the home invaded by syphilis or gonorrhea.
There are three venereal diseases : syphilis, gonorrhea, and chancroid. In order to have a clear understanding of the problems of venereal prophylaxis it is necessary to have a knowledge of the essential features of these preventable infections. Two of them, syphilis and gonorrhea, are of great importance, because they are very prevalent and because they are very serious infections with grave consequences. Gonorrhea is the great preventer, syphilis the great destroyer of life.
SYPHILIS
Syphilis is a specific infection caused by the Spirochcefa pallida.^ It is acquired by direct contact with infected persons, by inoculation with infected things, and by congenital transmission. Syphilis runs a chronic course with lesions and symptoms of extraordinary diversity. The initial lesion or chancre forms on the skin or mucous membrane at the site of entrance of the spirochetes. The period of incubation is never less than 10 days, with a maximum of 90 days. In the majority of cases, the chancre appears between the 14th and 40th days.
There are many striking things about syphilis, but nothing so strik- ing as its persistence in spite of knowledge complete enough to stamp
" Resolutions adopted by the Board of Health. February 20th. "°.4itn known as Treponema pallidum.
56 DISEASES HAVING SPECIAL PEOPHYLAXIS
it out and in view of the popular dread in which the disease is held. It is preventable, even curable — yet scarcely another disease equals it in the extent and intensity of its ravages. It is the great canker of humanity.
Syphilis is a good illustration of the fact that it is much more diffi- cult to control a disease transmitted directly from man to man than a disease transmitted by an intermediate host, or one in which the virus is transferred through our environment. We have a certain amount of control over our surroundings, and we have dominion over the lower animals, but the control of man requires the consent of the governed.
Civilization and syphilization have been close companions, but syph- ilis is now less prevalent among civilized than uncivilized peoples — this is promising. Civilization, however, should not be content until it has controlled syphilis as effectively as it has some other preventable infec- tions. The effort to do so, at least, must be persistent and sincere.
From the economic side syphilis is not a serious disease in its pri- mary and secondary stages; that is, persons with syphilis during the early stages are usually not ill enough to cease work.*^ Acutely fatal cases, such as frequently occurred in the sixteenth century, are now rare; in other words, the disease has lost much of its early virulence. It is the late manifestations, or the so-called parasyphilitic lesions, as well as the inherited consequences of the disease, that play havoc. About one-fifth of all the insane in our asylums are cases of general paresis; 90 per cent, of these give the Wassermann reaction. Syphilis, alcohol, and heredity fill our insane asylums, jails and almshouses.
The consequences of syphilis are often more severe upon the off- spring than upon the syphilitic parent. The infection itself, or various defects, especially of the nervous system, resulting from the conse- quences of syphilis, may be transmitted from parent to child, often with fatal results. When death does not ensue the results may be still more tragic.
The health officer should regard syphilis just as he does the acute febrile exanthematous diseases. Because syphilis runs a slow and often chronic course with mild constitutional symptoms during its early stages, it is often placed in a class by itself. This is a mistake. Syphilis has its period of incubation, eruption, and decline, just as measles and smallpox have.
Historical. — There is an accurate historical record of the startling spread of syphilis over the known world in a few years after 1495, and from that time it has everywhere been endemic. No similar record exists of the sudden establishment of any other great disease among the larger part of the earth's inhabitants. Evidence, however, points to the severe character of the disease during this early epidemic, the cases often run-
*9 But it is most communicable during this time.
VENEREAL DISEASES 57
ning an acute, febrile course, accompanied by symptoms of such severitv as are now seen only occasionally. Syphilis was unknown before the year 1493. It is said to have been brought by the crew of Columbus, on his first voyage from Espanola, or Hayti.'^" Some of the returning (Tcw acconiitanied Charles YIII of France in the autumn of 1 }!>1 with the army, 35,000 strong, which invaded Italy for the conquest of Xaples. The epidemic began in Italy at this time, and the disease spread quickly over Europe with the scattering of the troops. At first the French called it the Xcajjolitan disease, and the Italians called it the French pox, or Morbus Gallicus. The name of the disease was taken from a popular poem written by Fracastor in 1530 entitled, "Syphilis sive Morbus Gal- licus," in Avhich the symptoms are clearly described in the principal pastoral character — Syphilis.
In 1903, Metclmikoff and Eoux ^^ transmitted the disease to lower animals and demonstrated the prophylactic value of calomel inunctions, and also opened up a rich field of animal experimentation. In 1905, Schaudinn ^- discovered the cause and thus made diagnosis certain. In 190G, Wassermann, Xeisser and Bruck ^^ introduced the indirect method of diagnosis by serum reaction. In 1910, Ehrlich,^* after many years of experiment, gave to the world salvarsan, a specific, synthetic spirocheti- cide. In 1911, Xoguchi °^ cultivated Spirochceia pallida outside of the body and prepared luetin. In 1913, Xoguchi ^^ demonstrated the spirochetes in the brain of paretics and in the cord of a tabetic. This un- paralleled group of achievements, all the result of scientific work in laboratories, in 10 short years threw light upon the cause, mode of trans- mission, patholog}% treatment and prevention of the disease.
Prevalence. — The percentage of syphilitics in the population at large is difficult to determine. It is commonly estimated at about 8 per cent. The amount of infection in certain groups is given by Tedder as follows : Prostitutes, 50 to 100 per cent. ; tuberculous in institutions, 20 to 30 per cent. ; ^^ sick children in hospitals, 2 to 10 per cent. ; men- tally backward and idiots, 20 to 40 per cent.; criminals, 20 to 40 per cent.; presumabh' healthy men of the class that enlist in the regular army, 20 per cent. : this group represents unskilled labor and a certain percentage of the tradesmen. Among men of better families the per-
»/. A. M. A., June 12, 1915, LXVI. 24. p. 1962.
^^Ann. de VInst. Pasteur, 1903, p. 809.
".Ir6. a. d. k. iJsndhtsamte, 1905, XXII. p. 527.
"Deutsch. med. ^ychnschr., 1906, XXXII, p. 745.
^ Dw experimentelle Chemotherapie der ,^pirillosen, 1910, Julius Springer, Berlin.
''''Jour. Exp. Med., 1911, 99, p. 557.
"Jour. Exp. Med., 1913, XVII, p. 232.
" The prevalence of syphilis among the tuberculous in this country has been variously placed by different investigators on the basis of a clinical examination or a positive Wassermann, or both. Some of these are as follows: Vedder, 23.2 per cent.; Snow and Cooper, 20 per cent.; Petroff, 21. S per cent.; Lyons, 9.2 per cent.j Jones, 29 per cent.
58 DISEASES HAVING SPECIAL PROPHYLAXIS
centage varies from 2 to 10 per cent., depending upon age, marital con- dition and other factors. Among young women in the community, the percentage of syphilitic infections fluctuates between 3 and 20 per cent., depending upon age, marital condition, education and social status. As among men, the proportion of infections increases as we descend in the social scale. It is estimated that the rates for the colored race are at least double those for the white race. See also page 73.
Stages of the Disease. — Syphilis is divided into four stages which are not always well defined in time or sequence.
The chancre. — The primary stage consists of the chancre which forms at the site of the initial infection. The regional lymph node becomes enlarged and hard. The typical Hunterian chancre is an indurated and undulated ulcer in the skin or mucous membrane, and ap- pears about three weeks (not less than ten days) after the receipt of the infection. It is usually single and painless, but frequently is atypical, and may be but a trifling lesion. In the absence of a careful daily in- spection, it may exist many days before it is detected, or even escape notice altogether.
The chancre contains many spirochetes which may readily be seen with the dark field illumination. This is the best method of early diagnosis.. The Wassermann reaction usually does not become positive until from two to six weeks after the appearance of the chancre. It is important to examine every sore on the genitalia for spirochetes, for the initial lesion of syphilis often resembles a chancroid, sometimes only a gimple abrasion. Mixed infections are frequent.
The secondary stage is determined by a general invasion of spirochetes throughout the system, and is characterized by involvement of the lymph nodes, eruptions upon the skin and mucous membranes, fever, anemia, and other indications of a generalized infection.
The third stage is characterized by a localized granulomatous growth known as a gumma. Gummata may appear in almost any tissue or organ of the body.
A fourth stage, consisting of inflammatory and degenerative lesions of the heart, blood vessels and central nervous system, is often added to the picture, and occurs long years after the primary sore. This stage, formerly regarded as sequelae or parasyphilitic phenomena, is now known to be associated with spirochetes, and should be classed as a stage of the disease. This is the most serious and disabling stage of the disease and is a frequent cause of insanity or premature death. Examples of the chief manifestations of the late stage of syphilis are locomotor ataxia and dementia paralytica, also arteriosclerosis, aneurism, cere- brospinal syphilis, etc. The prevention of these serious conditions de- pends upon early recognition of the chancre, followed by prompt and thorough treatment.
VENEBEAL DISEASES 69
Fatality. — Syphilis is the chief cause of dcatli in early ailult life in persons otlicrwise hale and hearty.
If it be remembered that syphilis is the real cause of dealli in all cases of general paresis, locomotor ataxia, and aortic aneurysm, in many cases of apoplexy, and is a contributory cause of death in a host of other conditions, including many cases of pulmonary tuberculosis, the real influence of syphilis on the mortality rate begins to be suspected. Osier some time ago made the statement that "of the killing diseases, syphilis comes third or fourth." But recently from an analysis of the TJegistrar General's statistics for 1915, he estimates the actual deaths from syphilis in England and Wales at about 60,000, thus moving syphilis to the top of the list. Leredde estimates that s}'philis probably kills 25,000 persons each year in France.
According to Lenz,^'^ in the large cities, 25 per cent, of syphilitics die as the result of endarteritis (angina pectoris, aortic insufficiency, aneurysm), while 3 or 4 per cent, of syphilitics die from general paraly- sis, 1 or 2 per cent, from tabes and at least 10 per cent, more as the result of syphilitic lesions of the brain, liver and kidneys. Almost half of all syphilitics eventually succumb as the result of their infection. Syphilis is therefore the greatest cause of premature death of men in large cities.
Mattanschek and Pilcz ^^ found that of 413-i officers of the Austrian Army who contracted syphilis between the years 1800-1900, on January 1, 1912: 198 had general paralysis; 113 had locomotor ataxia; 132 had cerebrospinal syphilis; 80 suffered from different psychoses; 17 died of aneurj'sm; 147 died of tuberculosis; 20 died with syphilis designated as the cause; 101 developed myocarditis and arteriosclerosis, 86 of whom died from this condition.
Diag'nosis. — Early diagnosis and prompt treatment are the most practical and promising measures to control syphilis (page 85). The clinical symptoms are often atypical and elusive; reliance on laboratory tests is therefore imperative.
Darlc field illumination should be applied as a routine to every genital sore, by an expert. A single negative finding is not conclusive, and. should be repeated daily for several days. No local antiseptic should be applied until the diagnosis is established. One application of a spiroche- ticide, such as silver nitrate, mercury, copper sulphate, iodin or iodoform, is often sufficient to cause the disappearance of the spirochetes from the surface of the sore.
The Wassermann reaction becomes positive only after a general in- vasion of the spirochetes takes place. At the time of the first appear-
" Ueher die Haufigkeit der syphilitischen Sklerose der Aorta relatw zur geicehnlichen Athero-sklerose und zur Syphilis iiberhaupt, Med. Klinik, 1013, IX, 955.
''Med. Klinik, 1913, IX, 1544; also Berl. Klin. Wchnschr.. 1908, XLV, 1213.
60 DISEASES HAVING SPECIAL PEOPHYLAXIS
ance of the chancre this reaction is invariably negative. It appears by the tenth day in about 30 per cent, of cases, and is positive in 96 per cent, of all cases by the 40th day. The Wassermann reaction therefore cannot be depended upon for early diagnosis^ but soon becomes the most reliable laboratory test. It (see also p. 65) should be remembered, how- ever, that in a small percentage of syphilitics, the Wassermann reaction remains negative, while on the other hand it may become positive in other infections, such as yaws, and sometimes in tuberculosis, malaria, pneumonia, scarlet fever, and especially in diseases associated with de- ranged metabolism of the liver. We must be cautious in drawing con- clusions from positive Wassermanns in other diseases, for it is often difficult to rule out syphilis.
The hietin test is an anaphylactic reaction depending upon sensitiza- tion of the skin. It does not always appear, and then late in the disease. It is more useful in prognosis and as a guide to treatment than in diagnosis.
Methods of Transmission. — Syphilis is transmitted directly, in- directly, and congenitally.
In a large majority of all cases of syphilis, the infection is trans- mitted during sexual approach and usually as a consequence of adulter- ous relations. It is, therefore, spoken of as a venereal disease; many cases, however, are contracted out of venery. These innocent infections are more common than is ordinarily supposed. The spirochete is an animated corkscrew and can probably penetrate the unbroken mucous membrane and perhaps the skin, although a fissure or slight abrasion is the site of most chancres.
Marital Syphilis. — The subject is of great interest and importance because marital syphilis is so frequent, and because the individual so infected is an innocent victim of the disease, and usually remains ignorant of the infection, and therefore receives little or no treatment. The transmission of syphilis from wife to husband is comparatively rare. On the other hand, the transmission of disease from husband to wife is comparatively common. M. Dechambre says, "Syphilis is divided among husband and wife like the daily bread."
Extragenital Chancres. — Extragenital chancres constitute from 5 to 10 per cent, of the total infections with syphilis. Metchnikoff reports that a great number of cases of non-venereal syphilis occurs among chil- dren in Eussia, where peasants live huddled together and in ignorance. Genital syphilis is not necessarily due to immorality, since it frequently results from marital relations, and has occasionally followed the rite of circumcision. Extragenital chancres are usually acquired innocently but may be the result of improper practices. It is particularly desirable to make this distinction from the public health standpoint, as the measures taken to prevent syphilis resulting from immorality and syphilis
VENEREAL DISEASES 61
acquired accidentally are naturally quite different. Innocent syphilis, however, is generally the result i)y one or two removes of syphilis ac- quired by promiscuity.
Buikley,*"'" Munchheimer, and Eournicr "^^ have coHocteil from the literature 20,000 cases of extragenital chancre ; Scheuer ^- has analyzed 14,590 of these in regard to location : 3880 occurred on the lips, con- tracted mainly by kissing; ::^14-i on the arm, caused by the old- fashioned arm-to-arm vaccination; 1569 occurred on the breast, mainly of healthy wet nurses from syphilitic infants; 1104 on the tonsils; 897 on fingers and hands, chiefly of physicians, nurses and midwives; 753 were caused by circumcision, 181 by cupping, and 109 by tattooing.
Kissing. — It is difficult to treat this subject seriously, and yet it must be considered as the most important single method by which accidental syphilitic infection is transmitted. When the public understands that not only syphilis, but also pneumonia, influenza, common colds, sore throats, measles, scarlet fever, whooping cough, diphtheria, and many other infections may be transmitted through kissing, the practice will become automatically reduced to normal and proper limits. The danger from kissing is great when there are mucous patches or other open, lesions upon the mucous membrane of the mouth. The kissing party reported by Schamberg ®^ has become classic : Eight individuals acquired chancres of the lip from kissing a young man who also had a chancre of the lip. The percentage of infection was very high — eight were infected, only five or six escaped.
Indirect Transmission. — The list of articles that have conveyed the contagium by indirect transmission is comprehensive and includes towels, clothing, razors, handkerchiefs, surgical and dental instruments, pipes, et cetera ; a considerable number of infections have been traced to barber shops, drinking glasses, and minor operations. ' Congenital and hereditary transmission of syphilis, see p. 645.
Infectiousness of Lesions and Tissues. — The chancre is highly in- fectious from its first appearance until it is completely healed. Hence the importance of early diagnosis and prompt treatment.
All secondary lesions are potentially infectious because spirochetes have been demonstrated in all of them. The mucous patch is the sec- ondary lesion most commonly responsible for the transmission of the disease. Like the chancre, it fairly teems with spirochetes, it is com- paratively painless, and occurring on the mouth or genitalia it occupies the two regions of the body most commonly brought into close and intimate contact with persons of the opposite sex. The vast majority of
^Syphilis in the Innocent. Bailey and Fairchild, Xew York, 1894, p. 197. '^ Les Chancres Extragenitaux. Paris, 1897.
^ Die i<yphilis der Unschuldigen, Berlin, 1910, Urban and Schwarzen- berg.
'^J. A. M. A., 1911, LVII, p. 783.
62 DISEASES HAYING SPECIAL PROPHYLAXIS
infections are acquired from syphilitics in the primary or early secondary stages of the disease. Nevertheless, we must regard any uncured syphilitic as a possible source of infection. The secondary stage with its endless lesions may last for 29 years.
Tertiary lesions are infectious, although it was thought for many years that they were not. Practically, cases of infection from tertiary lesions are comparatively rare and only occur from late eruptions of the skin and superficial gummatous ulcerations.
The infectiousness of the hlood has been demonstrated in all stages of syphilis, but the danger from this source is slight. An exception to this statement is to be noted in the case of surgeons, physicians, nurses, dentists and midwives, among whom syphilis is the great occupational disease.
The milh of a syphilitic woman must be regarded as infectious, since it is well known that a syphilitic wet nurse without lesions will almost surely infect a healthy child ; the spirochetes therefore appear to be trans- mitted in the milk.
Spermatic fluid. — Warthin's findings *^* demonstrate that the seminal fluid from many secondary cases is infectious, and we may assume that the seminal fluid from tertiary cases may be infectious in the presence of a suitable lesion in the testicles, and this is confirmed by clinical experience, which indicates that some cases of syphilis appear to be transmitted in this way.
Spinal fluid is infectious in many cases in which the central nervous system is involved. The sputum, sweat and urine are generally believed not to be infectious, except in the presence of discharging lesions.
For public health purposes, a person suffering from syphilis is con- sidered to be in an infective stage so long as he shows any symptom or lesion of primary or secondary syphilis, or any discharging lesion of the tertiary stage. „,,,. v, ,'
Viability. — The spirochete of syphilis is a frail organism, yet it may live long enough on towels, glasses, razors, dental instruments, pipes, and other objects to command hygienic respect. Thus, Zinsser and Hopkins ^^ found that pure cultures lived IIV2 hours on a moist towel. Dried on covered slips, the spirochete failed to grow after one hour. Bronfenbrenner and Noguchi ^" found that the viability of the spirochete is markedly diminished by lack of nutritive substances, pres- ence of oxygen, effect of light, and the toxic effect of sodium chlorid.