UNIVERSITY OF CALIFORNIA 
 AT LOS ANGELES
 
 FORTY 
 
 NOTIFIABLE 
 
 DISEASES 
 
 A SIMPLE DISCUSSION OF THE MORE 
 IMPORTANT COMMUNICABLE DISEASES 
 
 BY 
 
 Hiram Byrd, B.S., M.D. 
 
 Director 
 
 Department of Hygiene 
 University of Alabama 
 
 WORLD BOOK COMPANY 
 
 Yonkers-on-Hudson, New York* 
 
 
 053* 
 
 19 flUID 22 
 
 4
 
 WORLD BOOK COMPANY 
 
 THE HOUSE OF APPLIED KNOWLEDGE 
 
 Established, 1905, by Caspar W. Hodgson 
 
 YONKERS-ON-HUDSON, NfiW YORK 
 
 2126 PRAIRIE AVENUE, CHICAGO 
 
 Our knowledge of infections and how to 
 prevent them is now so definite and so 
 complete that in this field of hygiene we 
 are able to rest most of our practices on a 
 sure basis of scientific truth. In conse- 
 quence our victories over these causes of 
 illness have been overwhelming, and with 
 the wider application of our knowledge 
 even more startling results will be secured. 
 Publisher and editor have pleasure in 
 offering in Forty Notifiable Diseases a 
 brief compend of important facts con- 
 cerning communicable diseases that should 
 be a part of the information possessed by 
 every American citizen. The author is an 
 experienced and practical worker who 
 knows exactly where effort should be di- 
 rected to secure a maximum health return. 
 
 Copyright, 1922, by World Book Company 
 
 Copyright in Great Britain 
 
 A II rights reserved 
 
 PRINTED IN V. 9. A.
 
 PREFACE 
 
 HYGIENE as a subject of general education has 
 taken on a new importance since the war. Every 
 year sees it introduced into more and more colleges 
 and universities, and with equal pace it is making 
 more and more definite inroads into the curricula 
 of the secondary schools. 
 
 But the subject matter is still unformed. Hardly 
 any two schools or individuals are approaching it 
 from the same angle. This condition grows quite 
 naturally out of the largeness of the subject and the 
 multiplicity of choices of material for emphasis. 
 Out of this situation comes the author's belief that 
 the time has arrived when we can profitably begin 
 the work of standardization. 
 
 Upon the theory that hygiene should ultimately 
 eliminate premature deaths and unnecessary suffering 
 and at the same time promote human efficiency, it 
 seems logical to direct our formative efforts toward 
 the points that are most likely to yield immediate 
 returns. 1 Those who have studied the subject most 
 the health authorities have, by common consent, 
 addressed themselves chiefly to the definite group 
 of diseases that forms the subject matter of this 
 little -book. 
 
 1 In the University of Alabama we devote one hour a week for 
 one year to hygiene as a required subject. Experience has shown 
 that in that time the students can acquire a "thinking knowledge" 
 of the notifiable diseases and a working knowledge of nutrition and 
 elimination. That is all we are undertaking to accomplish in this 
 course. 

 
 iv Preface 
 
 It might be asserted that an adequate treatment, 
 of the diseases presupposes a working knowledge of 
 biology that is not always available, even among 
 college groups. Yet it is believed that it is possible 
 to give to those denied such preliminary preparation 
 at least a thorough grounding in the principal facts 
 connected with these diseases. 
 
 The idea behind the publication of this book is, 
 then, to set forth only those salient facts of the 
 subject that the layman can reasonably be expected 
 to assimilate, but at the same time, if possible, to 
 include all the facts and ideas that are really impor- 
 tant for him to know and to express them in such 
 simple form as to enable him to begin to master 
 them before college or even high school is reached. 
 
 No apology is offered for the diminutive size of 
 the book; but if it be challenged upon the ground 
 that the language is too juvenile for grown-ups, then 
 answer is made that before beginning the work a 
 painstaking examination was made of over 2000 
 people, including college students and professors, 
 medical students, nurses, lawyers, and teachers, and 
 as a result of that examination the conclusion was 
 reached that there is far graver danger of shooting 
 over the head than under the feet. 
 
 H. B.
 
 CONTENTS 
 
 CHAPTER PAGE 
 
 INTRODUCTORY ...... 1 
 
 1. ABOUT GERMS 3 
 
 2. THE FORTY NOTIFIABLE DISEASES . . 9 
 
 3. FORTY NOTIFIABLE DISEASES CLASSIFIED AC- 
 
 CORDING TO CAUSE . . . ... 12 
 
 4. CHILDREN'S DISEASES . . . . 14 
 
 5. SEWAGE DISEASES ..... 16 
 
 6. DISEASES SPREAD BY SUCTORIAL INSECTS . 25 
 7. THE VENEREAL DISEASES .... 29 
 
 8. DISEASES AFFECTING ESPECIALLY THE NERV- 
 
 OUS SYSTEM ...... 32 
 
 9. DISEASES CONTRACTED FROM LOWER ANIMALS 35 
 
 10. DISEASES HAVING A WELL-DEFINED GEOGRAPH- 
 
 ICAL LIMITATION . . . . 37 
 
 11. DISEASES OF UNKNOWN CAUSATION . . 40 
 
 -12. SOME DISEASES WHICH MAY BE SPREAD 
 
 BY CARRIERS . . . . . . 45 
 
 13. DISEASES DUE TO FILTERABLE VIRUSES . 47 
 
 14. NINE DISEASES AMENABLE TO IMMUNIZATION 48 
 
 15. INTER-INFLUENCE OF DISEASE ... 59 
 
 16. TUBERCULOSIS ...... 61 
 
 17. THE SO-CALLED MADSTONE . . . 63 
 GLOSSARY 65
 
 'Tis his at last who says it best - 
 I'll try my fortune with the rest. 
 
 LOWELL
 
 INTRODUCTORY 
 
 MOST of the notifiable diseases are caused by 
 germs of one kind or another; hence, first of all, the 
 chapter "About Germs" should be read carefully 
 and thoughtfully, and, if necessary, re-read. 
 
 Then comes the list of "Forty Notifiable Dis- 
 eases." To most persons the very names of these 
 diseases look formidable, and instead of getting down 
 to business and learning them, these persons call 
 them "any old thing" and pass them by. It should 
 be understood at the outset that one cannot learn hygiene 
 without learning its language. Furthermore, as soon 
 as one becomes serious about learning the language 
 of hygiene, the difficulties all fade away. It is true, 
 "poliomyelitis" is a long word, but it is not so long 
 as "Constantinople," and who cannot spell and 
 pronounce "Constantinople"? So many medical 
 terms are built up from familiar components that as 
 soon as the structure of one of these words is noted, 
 the meaning becomes at once apparent. For example, 
 all the "itises" are simply inflammations, as inflam- 
 mation of the appendix, of the bronchi, of the tonsils, 
 or of the colon (lower bowel); "hem" or "em" has 
 reference to blood, as anemia (without blood), hyper- 
 emia (too much blood, congestion), hemorrhage (a 
 flowing of blood), or /tematuria (blood in the urine); 
 all the "zos" pertain to animals, as Zoology; all the 
 "phytes" pertain to plants, as epiphyte (upon a 
 plant); the "hypers" mean "over," or too much, 
 as /hypersensitive, hypertension; the "hypos" mean 
 "under," as hypodermic (under the skin); and 
 
 i
 
 2 Forty Notifiable Diseases 
 
 "derma" means "the skin," as epiderm (upon the 
 skin), or cfermaphyte (a skin plant, of which the 
 mold-like plants that cause "ringworms" are good 
 examples). 
 
 So after reading the chapter "About Germs," it 
 is urged that the names of these "forty notifiable 
 diseases" be learned thoroughly the spelling, the 
 pronunciation, and above all the meaning. Through- 
 out the course a dictionary may be used to advantage. 
 
 At the head of the list of diseases, the term " Regis- 
 tration Area" is used. Stop and find out what that 
 term means before proceeding further. Incidentally 
 scan the list and decide for yourself which are the 
 most important diseases in it. 
 
 It will be noted that many of these diseases are 
 treated in groups. This grouping is a teaching device 
 and is admittedly more or less artificial. 
 
 Although the language of hygiene is insisted on, 
 at the same time technical terms have been avoided 
 in the work as far as possible.
 
 CHAPTER ONE 
 ABOUT GERMS 
 
 THERE is probably no word in the English language 
 more widely misunderstood than the word "germ." 
 This wholesale misunderstanding clusters chiefly 
 around four points the idea that germs are uni- 
 versally "mean," their size, their numbers, and the 
 way they travel. 
 
 A little history will help to clarify some points. 
 It was Louis Pasteur who started all the talking 
 and writing about germs and bacteria and microbes 
 that has taken place during the past forty or fifty 
 years. When, away back in the '60's, a great epi- 
 demic disease struck the silkworms of France and 
 was playing greater havoc with the silkworm industry 
 than the boll weevil is with the cotton industry in 
 our own country, Pasteur took up the disease, hoping 
 to find its cause and possibly how to prevent it. 
 He soon found in the sick silkworms tiny little bodies 
 that were not in the well worms. These little bodies 
 were alive. He found that if some of them were 
 put on the food of the well worms, these worms soon 
 got sick with the same disease and that the same 
 kind of little bodies could then be found in them. 
 In fine, he had discovered germs. This was the first 
 tune in the world that it was definitely proved that 
 little living things caused disease. 
 
 It was not long after this that Koch discovered 
 that consumption in human beings was also caused 
 by little living things or "germs." Soon Hansen 
 found that leprosy was caused by germs. Klebs 
 
 3
 
 4 Forty Notifiable Diseases 
 
 proved that diphtheria was a germ disease, and 
 Eberth found the germ that caused typhoid. By 
 this time it was generally recognized that all com- 
 municable disease is caused by living organisms. 
 
 All these findings were noted in the papers, and 
 people began to read and ponder. At that time a 
 "germ" was supposed to be about the worst thing 
 in the world. Nurses used to frighten the babies 
 by telling them that if they did not hush, a "germ" 
 would get them. No one ever heard in popular 
 literature of a good germ no one ever thought of 
 one even. 
 
 But there are good germs, nevertheless. They 
 outnumber the bad ones by far. They do a great 
 deal more good than the bad ones do harm. It is 
 only through the agency of "germs" that wine and 
 beer can be made. Wine and beer are in bad repute, 
 but germs are still useful. All the plain and fancy 
 cheeses are made through the agency of germs. 
 Whenever you take a vanilla soda or vanilla ice 
 cream, you pay tribute to germs, for the vanilla 
 bean has to be fermented before the vanilla flavor 
 is developed. In the preparation of linen, the flax 
 has to undergo a process of fermentation called 
 "retting." 
 
 But, more important than all this, it is now under- 
 stood that germs are of inestimable value to agri- 
 culture. Germs take from the air free nitrogen, 
 which plants cannot use, and build it up into nitrates 
 that can be used by plants; and in turn animals 
 obtain these nitrates by eating the plants. Then,
 
 About Germs 5 
 
 when these plants and animals die, other germs tear 
 their bodies down and let loose the nitrogen once 
 again. Thus the air is kept supplied with its full 
 amount of nitrogen. Even the nitrates that leak 
 away into the rivers and seas are attacked there 
 by germs that break up these nitrates and release 
 their nitrogen so that it flows again into the air. 
 
 This circle of changes through which nitrogen 
 passes is known as the nitrogen cycle, and were it 
 not for the germs, the cycle would be broken. When 
 an animal or plant died, instead of being broken 
 down and its nitrogen released for further use by 
 other plants and animals, it would remain in a state 
 of preservation indefinitely. The atmospheric nitro- 
 gen would be all tied up in these dead organisms, 
 and the circulation of nitrogen in the world would 
 cease forever. So whenever you are tempted to 
 think ill of a germ, remember that all life depends 
 for its existence on the activities of these little germs. 
 Oh, yes, there are a few dozen harmful ones, it is 
 true, but there are hundreds that are beneficial. 
 
 The second great misunderstanding about germs 
 concerns their size. The untrained find it difficult 
 to think of anything as small as a germ really is. 
 They think to a certain point in Littleness, and then 
 when they try to think of anything smaller, first 
 doubt and then incredulity creeps in. 
 
 But really germs are as small as the bacteriologists 
 say they are. For example, the germs of tuberculosis, 
 which are shaped about like corncobs, are so small 
 that, laid end to end, it would take 10,000 to measure
 
 6 Forty Notifiable Diseases 
 
 an inch, and laid side by side, it would take 80,000 
 to measure an inch! A mass of tuberculosis germs 
 as large as a drop of water could contain enough 
 for every man, woman, and child on the face of the 
 earth to have one apiece, and even then some would 
 be left over. A patient in an advanced stage of 
 tuberculosis might cough up and spit out enough 
 germs every day to infect every person in the world 
 a thousand times over. 1 
 
 We often speak of germs growing. We do not 
 exactly mean by that that they get larger; we mean 
 rather that they increase in numbers. They do this 
 very rapidly. As a matter of fact they do grow a 
 little in size; but they soon break in two, and each 
 half becomes a new germ. In turn, each one of 
 these new germs grows in size a little and breaks 
 again, and so on. Under favorable conditions it 
 takes them only about 20 minutes to grow a little 
 and break in two. Suppose one were grown under 
 favorable conditions, how many would come from 
 it in 24 hours? 
 
 Starting at 12.00 o'clock, we should have 1 perm 
 
 " " " 2 germs 
 
 u 
 
 12.20 
 
 12.40 
 
 1.00 
 
 1.20 
 
 1.40 
 
 4 
 
 8 
 
 16 
 
 32 
 
 " u 2.00 " " " " 64 " 
 
 u o >| ) u K u 1 90 u 
 
 " 2.40 " " u " 256 " 
 
 1 Thousand in this sense is used only as a figure of speech; it is 
 not an overstatement, but actually an understatement.
 
 About Germs 7 
 
 Starting at 3.00 o'clock, we should have 512 germs 
 a u 320 1,024 " 
 " " 3.40 " " " 2,048 " 
 
 400 a a 4^95 a 
 
 a 420 8,192 " 
 " 4.40 " " " " 16,384 " 
 
 A. Fischer has completed the calculation for the 
 24-hour period and states that at the end of this 
 period there would be 1600 trillion new germs! But 
 it is only when they have the right kind of nutrition 
 and environment that they multiply at such a rate 
 or at all, for that matter. 
 
 A knowledge of their smallness and numbers paves 
 the way for an understanding of their methods of 
 travel. You know how easily coal dust sticks to a 
 person's skin or to clothes. You know also how dirt 
 rubs off and soils other things with which it comes 
 in contact, and how such dirt is thus carried from place 
 to place. That is about the way germs travel not 
 such aristocratic germs as malarial parasites, that 
 travel by "flying machines," as we shall learn later, 
 but the common germs of tuberculosis or diphtheria, 
 which have to get around in the best way they can. 
 
 Germs may be either small plants or small animals. 
 The ones most commonly met with are little plants 
 that are called bacteria (singular, bacterium). The 
 simplest and most common form encountered among 
 these is the spherical. A spherical bacterium is called 
 a coccus (plural, cocci). 
 
 In reproducing, a coccus grows a tiny bit and then 
 splits in half. Sometimes these two halves do not
 
 8 Forty Notifiable Diseases 
 
 separate entirely but cling together, giving the 
 appearance of two cocci fastened lightly to each 
 other. Groups of cocci arranged like this are called 
 diplococci. Three of our forty diseases are caused 
 by diplococci; namely, meningitis, gonorrhea, and 
 pneumonia. 
 
 Sometimes the cocci, instead of arranging them- 
 selves in twos, arrange themselves in a long chain, 
 like a string of beads. This arrangement of cocci is 
 called streptococci. None of our notifiable diseases 
 are known to be caused by streptococci, but ery- 
 sipelas and puerperal (childbed fever) are caused 
 by this group of cocci. Occasionally streptococci 
 also attack the throat, causing distressing symptoms. 
 
 Sometimes the cocci arrange themselves in clusters 
 like a bunch of grapes. Grouped thus, they are 
 called staphylococci. It is the germs of this group 
 that commonly cause boils. 
 
 Others of these vegetable germs, instead of being 
 round, are rod-shaped, something like a corncob. 
 Such germs are called bacilli (singular, bacillus). 
 The germs of tuberculosis, typhoid, paratyphoid, 
 bacillary dysentery, glanders, and leprosy are all 
 bacilli. The bacilli of anthrax often arrange them- 
 selves in chains, called streptobacilli. 
 
 Besides the round and the rod-shaped germs there 
 is still another group, composed of those having a 
 spiral or corkscrew shape. These are collectively 
 known as spirilla (singular, spirillum). The germ 
 of Asiatic cholera belongs to this group.
 
 CHAPTER TWO 
 THE FORTY 1 NOTIFIABLE DISEASES 
 
 IN the table on page 11 the forty notifiable dis- 
 eases which we are to study in detail are arranged 
 in the order of the number of deaths caused by each 
 in the Registration Area of the United States in 
 1917, paralleled with the number of deaths from 
 the same diseases in the great epidemic year of 1918. 
 
 The Death Registration Area of the United States 
 (exclusive of Hawaii) consists of 34 states, the Dis- 
 trict of Columbia, and 16 cities in the non-registra- 
 tion states. The 14 states not in the Registration 
 Area are: 
 
 Alabama Iowa South Dakota 
 
 Arizona Nevada Texas 
 
 Arkansas New Mexico West Virginia 
 
 Georgia North Dakota Wyoming 
 
 Idaho Oklahoma 
 
 A state or city is admitted to the Registration Area 
 whenever it makes provision for reporting accurately 
 90 per cent or more of all deaths occurring within 
 its bounds. 
 
 The Birth Registration Area is not quite so large 
 as the Registration Area for deaths, and includes 
 only those states (not cities) that are reporting 90 
 per cent of all births occurring within their bounds. 
 In 1919 it consisted of 22 states and the District of 
 Columbia, as follows: 
 
 1 "Forty" is not to be taken literally. The actual number of 
 notifiable diseases varies from state to state. Besides, this does not 
 include industrial diseases that are, in many states, notifiable. 
 
 9
 
 Forty Notifiable Diseases 
 
 California 
 
 Connecticut 
 
 District of Columbia 
 
 Indiana 
 
 Kansas 
 
 Kentucky 
 
 Maine 
 
 Maryland 
 
 Massachusetts 
 Michigan 
 Minnesota 
 New Hampshire 
 New York 
 North Carolina 
 Ohio 
 Oregon 
 
 Pennsylvania 
 
 South Carolina 
 
 Utah 
 
 Vermont 
 
 Virginia 
 
 Washington 
 
 Wisconsin 
 
 This area embraces 58.6 per cent of the estimated 
 population of the United States.
 
 TABLE 1 
 
 Disease 
 
 DEATHS 
 1917 
 
 DEATHS 
 1918 
 
 Tuberculosis (all forms) 
 
 Pneumonia 
 
 Cancer 
 
 Influenza 
 
 Diphtheria (together with croup and septic 
 
 sore throat) 
 
 Measles 
 
 Typhoid (including also paratyphoid) .... 
 
 Whooping-cough 
 
 Syphilis . 
 
 Meningitis 
 
 Dysentery (amebic, bacillary, and others) . . 
 
 Pellagra 
 
 Scarlet fever 
 
 Malaria 
 
 Tetanus (lockjaw) 
 
 Encephalitis 
 
 Gonorrhea 
 
 Cholera nostras 
 
 Smallpox 
 
 Rabies (hydrophobia) 
 
 Anthrax 
 
 Mycoses (actinomycosis and others) .... 
 
 Hookworm disease 
 
 Leprosy 
 
 Typhus 
 
 Glanders 
 
 Chancroid (not fatal) 
 
 Chicken pox (not fatal) 
 
 Asiatic cholera (no cases) 
 
 Dengue (not fatal) 
 
 Favus (not fatal) 
 
 German measles (not fatal) 
 
 Bubonic plague (no cases) 
 
 Poliomyelitis (infantile paralysis) (sometimes 
 
 fatal) 
 
 Rocky Mountain spotted fever (sometimes 
 
 fatal) 
 
 Trachoma (not fatal) 
 
 Trichinosis (rarely fatal) 
 
 Yellow fever (no cases) 
 
 Mumps (not fatal) 
 
 II 
 
 110,144 
 74,517 
 61,429 
 12,965 
 
 12,442 
 
 10,442 
 
 10,089 
 
 7,837 
 
 7,795 
 
 6,673 
 
 4,546 
 
 3,666 
 
 3,124 
 
 2,385 
 
 1,329 
 
 620 
 
 595 
 
 242 
 
 204 
 
 66 
 
 61 
 
 39 
 
 29 
 
 17 
 
 16 
 
 4 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 121,204 
 
 167,703 
 
 65,282 
 
 234,290 
 
 11,183 
 
 8,223 
 
 10,167 
 
 13,728 
 
 7,522 
 
 7,500 
 
 4,720 
 
 3,711 
 
 2,335 
 
 2,534 
 
 1,276 
 
 687 
 
 500 
 
 299 
 
 248 
 
 63 
 
 34 
 
 46 
 
 28 
 
 24 
 
 3 
 
 4 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 CHAPTER THREE 
 
 FORTY NOTIFIABLE DISEASES CLASSIFIED 
 ACCORDING TO CAUSE 
 
 IN the table below the forty notifiable diseases 
 have been arranged in convenient form for ready 
 reference and comparison as to their general causes. 
 
 TABLE 2 
 
 1. Actinomycosis X 
 
 Anthrax X 
 
 3. Cancer 2 . . 
 
 4. Chancroid 
 
 5. Chicken pox 
 
 6. Cholera 
 
 Asiatic X 
 
 Nostras 
 
 7. Continued fever (not a disease 
 
 entity) 
 
 8. Dengue 
 
 9. Diphtheria X 
 
 10. Dysentery 
 
 Amebic . 
 
 Bacillary X 
 
 11. Encephalitis (lethargic) 
 
 12. Favus X 
 
 13. German measles 
 
 14. Glanders X 
 
 Gonorrhea X 
 
 I 
 
 X 
 
 \ 
 
 X 
 X 
 
 X 
 X 
 
 1 S*^ page 47. 2 Presumably not caused by germs. 
 
 12
 
 Diseases Classified According to Cause 
 
 TABLE 2 (Continued) 
 
 13 
 
 
 KNOWN VEGETABLE 
 GERM 
 
 KNOWN ANIMAL 
 GERM 
 
 GERM NOT KNOWN 
 
 FILTERABLE " VIRUS"' 
 
 16. Hookworms 
 
 
 X 
 
 
 
 17. Influenza 
 
 X 
 
 
 
 
 18. Leprosy 
 
 X 
 
 
 
 
 19. Malaria 
 
 
 X 
 
 
 
 20. Measles 
 
 
 
 
 X 
 
 21. Meningitis (cerebrospinal fever) . 
 22. Mumps 
 
 X 
 
 ? 
 
 
 
 
 23. Paratyphoid 
 24. Pellagra 2 
 
 X 
 
 
 
 
 25. Plague 
 
 X 
 
 
 
 
 26. Pneumonia 
 
 X 
 
 
 
 
 27. Poliomyelitis 
 28. Rabies 
 
 X 
 
 
 X 
 
 X 
 X 
 
 29. Rocky Mountain spotted fever 
 30. Scarlet fever 
 
 
 
 X 
 X 
 
 ? 
 
 31. Smallpox 
 
 
 
 X 
 
 X 
 
 32. Syphilis 
 
 
 X 
 
 
 
 33. Tetanus 
 
 X 
 
 
 
 
 34. Trachoma 
 
 
 
 X 
 
 X 
 
 35. Trichinosis 
 
 
 X 
 
 
 
 36. Tuberculosis 
 
 X 
 
 
 
 
 37. Typhoid 
 
 X 
 
 
 
 
 38. Typhus 
 
 
 
 X 
 
 
 39. Whooping-cough 
 
 X? 
 
 
 ? 
 
 
 40. Yellow fever 
 
 
 X 
 
 
 X 
 
 !See page 47. 
 
 * Presumably not caused by germs.
 
 CHAPTER FOUR 
 
 CHILDREN'S DISEASES 
 
 Chicken pox Scarlet fever 
 
 German measles Whooping-cough 1 
 
 Measles Smallpox 
 
 FIVE of the six foregoing diseases are commonly 
 known as children's diseases, but smallpox has so 
 many points in common with the others that it is 
 included. 
 
 Chicken pox and German measles rarely, if ever, 
 cause a death and would not be included among 
 the notifiable diseases but for the reason that through 
 mistaken diagnosis epidemics of smallpox and mea- 
 sles may get started. 
 
 Measles, scarlet fever, and whooping-cough are 
 really serious diseases among children. By reference 
 to Table 1 it will be seen that in 1917 in the Regis- 
 tration Area measles caused over 10,000 deaths, 
 while whooping-cough caused over 7000 and scarlet 
 fever over 3000. 
 
 Children should never be rushed info these diseases 
 to get them and ''have it over." 
 
 Smallpox, although it has been in the history of 
 the world a great scourge, has been "vaccinated to 
 death," so that at present it is of little consequence, 
 causing only one fiftieth as many deaths as measles. 
 
 1 In 1906 Bordet and Gengou isolated what they thought was 
 the germ of whooping-cough, but their claims have not been univer- 
 sally accepted. On the theory that this germ is the cause of whooping- 
 cough, a corresponding vaccine against the disease has been placed 
 on the market, but it cannot be said to be beyond the experimental 
 stage. 
 
 14
 
 Children s Diseases 15 
 
 The members of this group have many points in 
 common: they are all contagious; the cause of each 
 is unknown; all date to a definite exposure, followed 
 by an incubation period, and then a rather sudden 
 onset (except in the case of whooping-cough, which 
 begins more gradually); all cause more or less rise 
 of temperature and a quickening of the pulse; all 
 are self-limited (that is, the patients get well or die, 
 as the case may be, within a fairly definite period) ; 
 all leave the individual immune; all have an erup- 
 tion, except whooping-cough; and all are managed 
 alike, except smallpox, which, being the one member 
 of the group against which we can vaccinate, is in 
 consequence the one member that is most perfectly 
 controllable. 
 
 It has been customary time out of mind to try 
 to control these diseases by quarantine, but so many 
 mild cases occur, that are never reported to the 
 health authorities and accordingly escape quarantine 
 restrictions, that quarantine methods are only in 
 part effective. Smallpox can be effectively controlled 
 by vaccination of those exposed or likely to be 
 exposed.
 
 CHAPTER FIVE 
 
 SEWAGE DISEASES 
 
 Typhoid fever 1 Bacillary dysentery 
 
 Paratyphoid fever Amebic dysentery 
 
 Asiatic cholera Hookworm disease 
 
 THE first four of these six diseases typhoid fever, 
 paratyphoid fever, Asiatic cholera, and bacillary 
 dysentery are due to well-known vegetable germs; 
 of the last two. one amebic dysentery is caused 
 by a minute animal organism, the ameba, and the 
 other by a worm, the hookworm. 
 
 These six diseases have three important points in 
 common: (1) they are all due to living organisms; 
 (2) the chief locus of the trouble is in the intestinal 
 tract; and (3) the chief desideratum in all is their 
 prevention through proper sewage disposal. 
 
 In studying this group of diseases the first thing 
 to determine is how the germs get from the alimen- 
 tary tract of the sick to the alimentary tract of the 
 well and thereby spread the disease. In amebic 
 dysentery, which will be considered first, the way is 
 not devious, but very direct. The amebae (little 
 animals too small to be seen with the naked eye) 
 are excreted in the stools. A person with amebic 
 dysentery is giving them off literally by the millions. 
 Now whenever these amebic stools find their way 
 into drinking-water and are swallowed, the deed is 
 accomplished. This seems to be the only way amebic 
 dysentery is ordinarily spread. It is not spread by 
 
 1 Entirely different from typhus fever. 
 16
 
 Sewage Diseases 17 
 
 flies as is the typhoid germ or that of bacillary dysen- 
 tery; and ordinarily it has no way of contaminating 
 milk. One can imagine it contaminating oysters and 
 running the gantlet that way. 
 
 An epidemic of one of these diseases that once 
 occurred at Tampa, Florida, was caused in an un- 
 usual manner. The vegetable gardens at Ybor City, 
 a suburb of Tampa, were flooded during the heavy 
 rains. Soon after the rains subsided, lettuce came 
 into the market (lettuce, it will be remembered, is 
 usually eaten raw). Following this incident there 
 occurred in Tampa an epidemic of typhoid fever 
 and a considerable increase of amebic dysentery. 
 However, accidents of this kind are rare, and in 
 public health practice it is customary to consider 
 any appreciable increase in the prevalence of amebic 
 dysentery as proof of sewage contamination of the 
 community drinking-water. 
 
 The amebae of dysentery leave the body of the 
 sick person only in the stools; but the germs of some 
 of the other diseases (e.g., of typhoid and para- 
 typhoid), besides leaving it in the stools sometimes 
 leave it in the urine also, and occasionally they 
 escape in the saliva (as in typhoid, for example). 
 This multiplies opportunities for spreading these 
 diseases. Indeed, the chances of infection through 
 contaminated drinking-water are so great that some- 
 times we have great water-borne epidemics, par- 
 ticularly of Asiatic cholera; whereas the prevalence 
 of amebic dysentery can hardly ever be said to reach 
 epidemic proportions. Then there are other ways
 
 18 Forty Notifiable Diseases 
 
 of spreading these diseases. A person in attendance 
 upon a case of typhoid fever, say, will get the infection 
 on his hands. Soon the hands go to the mouth and 
 some of the germs are left there. This method of 
 transmitting the disease is known as finger infection. 
 Finger infection is common where the patient is 
 cared for by untrained help. Sometimes, even now, 
 typhoid fever goes nearly through a family by finger 
 infection. 
 
 But finger infection is only one way by which the 
 typhoid bacilli get from the intestine of the sick to 
 the intestine of the well. There are other ways. 
 Suppose the stools from one of these patients are 
 thrown out in the open. Flies are soon attracted to 
 them. The flies feed on them, at the same time 
 walking over them and getting the germs on their 
 feet. Then they fly to the house, into the dining 
 room, and walk over the food. If we had eyes a 
 thousand times as fine as we have, we could see, 
 wherever a fly walks after coming from one of these 
 open privies, a trail of germs like mud tracks on a 
 clean floor. An experimenter once let a fly walk 
 across a plate of sterile gelatin. The germs that it 
 left in its tracks grew and multiplied, and by the 
 next day they were so numerous that they could 
 be seen with the naked eye. There were little masses 
 of germs wherever the fly had put its foot down. 
 When flies carry the germs from typhoid stools to 
 food, the method of transmission is called fly in- 
 jection. 
 
 Again, when a person gets well from typhoid, he
 
 Sewage Diseases 19 
 
 may still excrete the germs for weeks or months, or 
 even years afterward. In this case he is known as a 
 typhoid carrier. Typhoid carriers spread the germs in 
 their wake and are often the means of spreading the 
 disease. This is particularly true when the carrier 
 happens to be engaged as a milker or cook. 
 
 There was once a famous typhoid carrier in New 
 York, known as "Typhoid Mary." She was a cook, 
 and wherever she took service the family sooner or 
 later developed typhoid fever. Sixty-seven cases of 
 the disease were traced to this one cook. 
 
 You have doubtless heard of typhoid from milk. 
 About the only way we get typhoid from milk is 
 through the agency of a typhoid carrier engaged 
 as a milker. A number of epidemics have been traced 
 to this cause. But today in well-managed dairies all 
 milkers are examined to make sure that they are 
 not typhoid carriers. 
 
 Now all that has been said about typhoid may 
 be said also, with perhaps a little less emphasis, 
 about paratyphoid, Asiatic cholera, and bacillary 
 dysentery. 
 
 This disposes, then, of five of the six sewage dis- 
 eases. It has been seen that the amebae leave the 
 body only in the stools, and that they find their 
 way into the bodies of others only through con- 
 taminated drinking-water. The germs of typhoid, 
 paratyphoid, Asiatic cholera, and bacillary dysentery 
 leave the body through the stools, and sometimes, 
 as in typhoid, through the urine and saliva. They 
 find their way to the mouths of others not only
 
 20 Forty Notifiable Diseases 
 
 through drinking-water, but by fingers, flies, and 
 food (milk in particular). It now remains to see 
 how the hookworms get from one person to another. 
 
 Unlike the ameb and the typhoid germs, the 
 hookworms do not leave the human body to get 
 to other people; they just send their eggs. The worms 
 remain in the intestine, feeding and laying eggs. 
 Now the eggs and this is an important point do 
 not hatch in the intestine. They must pass out in the 
 stools and get to the air before hatching will take 
 place. When a child has hookworms, his stools are 
 loaded with eggs. These eggs are too small to be 
 seen with the naked eye, but they can be seen under 
 a microscope and in that way the doctor can deter- 
 mine if a child has hookworms by finding the 
 eggs. Let us follow these eggs after they have passed 
 out in the stools. If the stools are passed into a 
 sewer, the eggs go out into the river, or wherever 
 the sewer empties, and are devoured by the tiny 
 animals that together with tiny plants go to make 
 up the plankton; or if they are not thus destroyed, 
 they disintegrate they never hatch. 
 
 On the other hand, suppose the stools are deposited 
 on the ground in a shady damp place, as along a 
 watercourse. Here they find ideal conditions and 
 soon hatch. These eggs, bear in mind, are so small 
 that it takes a microscope to see them; and the worm 
 that hatches out is also microscopic in size. They 
 can live in this damp soil for a long time. They 
 even grow a little and moult, and then look as if 
 they were going to moult again; that is, they seem
 
 Sewage Diseases 21 
 
 to get loose from their outside skin, but they stay 
 inside of it, so that they look like little wiggly cap- 
 sules. In this condition they are ready for business. 
 
 Their business is to get into the intestine of a 
 child. 1 They cannot go out and hunt a child, they 
 just have to wait and chance one coming along. 
 Myriads of them die while waiting. But occasionally 
 the child comes along and they make connection. 
 He must be barefoot or have holes in his shoes, for 
 the little worms cannot get through leather. But 
 let us suppose that one of these worms has been 
 able to come in contact with the child's bare foot. 
 This worm, capsule and all, wiggles his way into 
 the pores of the skin (the pores, it should be under- 
 stood, do not go all the way through the skin). 
 When the worm comes to the end of the little hole 
 or pore which he has entered, he pushes through 
 his capsule and goes right on through the remainder 
 of the skin and on into the foot of the child. The 
 capsule he leaves behind, in the skin. It is probably 
 this capsule or outer skin of the young hookworm, 
 left in the skin of the child, that causes the itching 
 known as "ground itch." We shall not stop to discuss 
 the ground itch now, but shall follow up the little 
 worm's journey. 
 
 When he gets through the skin of the child's foot, 
 he gets into the blood vessels. Here he finds himself 
 in the blood stream, and traveling becomes easier. 
 
 1 In this country children are the chief sufferers from hookworm 
 disease, but adults are also susceptible and in some countries the 
 disease is widespread among the adult population.
 
 22 Forty Notifiable Diseases 
 
 He is just carried along with the current of blood, 
 and on he goes. This blood stream is very, very 
 small at first, but gets larger as other vessels join it, 
 and as it approaches the heart it is as large as one's 
 little finger. After the worm has gone through the 
 heart and has come out on the other side, he goes 
 straight toward the lungs. Then the vessels get 
 smaller and smaller, and about the time he gets to 
 the lungs he is so cramped that he cannot go any 
 farther and cannot even turn over in the little blood 
 vessel. He is now in the capillaries of the lungs. 
 These little capillaries have such thin walls that 
 the oxygen we breathe just goes through the capillary 
 walls into the blood, and the carbon dioxid goes 
 through the same thin walls the other way to be 
 thrown off. The little worm is now at one of the 
 most interesting places in the body. If he could 
 only understand things at this juncture! Thousands 
 of millions of little red blood corpuscles are all around 
 him, each acting as if it were a thing alive, and busy 
 laying off its cargo of carbon dioxid and taking on 
 a cargo of oxygen for remote parts of the body. 
 But the little worm does not tarry here long. There 
 is nothing between him and the outside air in the 
 lungs but the thin membrane, and he soon breaks 
 through that and finds himself in the air spaces of 
 the lungs. 
 
 In the lungs the little worm is a foreign body, 
 and a foreign body in the lungs causes coughing. 
 So the child coughs; gradually the worm is raised 
 till he gets to the throat and is swallowed. Now he
 
 Sewage Diseases 23 
 
 goes straight into the stomach, and then on through 
 it, into the intestine. How he gets through the 
 stomach without being digested like any other tiny 
 piece of meat is more than I can tell, but he seems 
 to do it at any rate he finally stops in the intestine, 
 where he attaches himself to the lining and begins 
 to suck like a baby possum. You know that when 
 a possum is born, it is very, very small. Its 
 mother puts it into the pouch and attaches its mouth 
 to a little nipple found there. The little possum 
 remains attached to that nipple through thick and 
 thin, sucking when hungry, and growing and growing 
 until it is too large for the pouch. That is the very 
 way the baby hookworm does. You should know 
 that in the intestines are thousands of little nipples 
 called villi. The baby hookworm seizes a group of 
 these and goes to sucking; but he does not get milk 
 he gets blood. On this food the young hookworms 
 grow until they are full-grown hookworms. 
 
 That is the life history, or the circuit, of the hook- 
 worm. It begins in the intestine of one child and 
 ends in that of another. It takes about six weeks 
 from the time the child has ground itch until the 
 young worms reach the intestine, grow up, and begin 
 to lay eggs themselves. 
 
 The ground-itch route is the chief method of 
 spread of hookworm infection, but it has been shown 
 that young hookworms may live for some time on 
 vegetables, and it seems certain that the infection 
 may be acquired through eating such infected 
 vegetables raw. This would explain how it is that
 
 r 
 
 24 Forty Notifiable Diseases 
 
 adulls, whose feet are protected by shoes, sometimes 
 become infected. 
 
 This completes our discussion of the sewage-borne 
 diseases. Summing up: first, we have amebic dysen- 
 tery, strictly water-borne; next, the vegetable group 
 - composed of typhoid, paratyphoid, Asiatic cholera, 
 and bacillary dysentery which are transmitted 
 through water, and also by flies, fingers, and food; 
 and last, the hookworm, which generally travels by 
 the ground-itch route, less commonly by infected 
 vegetables. From these facts it is clear that every 
 one of these six diseases would disappear from the 
 face of the earth if all sewage were properly disposed 
 of. Perhaps the world's greatest sanitary problem 
 today is the disposal of human excrement. Victor 
 Heiser has estimated that even today there are 100 
 million people in the world perennially sick from im- 
 proper methods of sewage disposal, although its 
 dangers have been known since the time of Moses, 
 some thousands of years ago.
 
 CHAPTER SIX 
 DISEASES SPREAD BY SUCTORIAL INSECTS 
 
 Dengue Plague 
 
 Malaria Typhus fever 
 
 Yellow fever Rocky Mountain spotted fever 
 
 OF the forty diseases under discussion, parasites 
 of six (those listed above) manage to get from host 
 to host through the aid of other parasites. Each 
 of these disease-producing pairs of parasites has a 
 system of teamwork which is hard to break up. 
 The parasites causing dengue, malaria, and yellow 
 fever have mosquitoes as partners in their iniquity; 
 the parasite causing plague is carried from rat to 
 rat and from rat to man by fleas; the typhus-fever 
 parasite is a "buddy" of the head and body lice; 
 and the parasites of the Rocky Mountain spotted 
 fever chum with the lowly tick. 
 
 The malarial parasites were discovered about forty 
 years ago. They are now so well known that they 
 have even been separated into different species, at 
 least three of which are recognized by biologists. 
 The plague parasite has been known since 1894, 
 but the yellow-fever parasite was not discovered 
 until three years ago. The germs of the remaining 
 three dengue, typhus fever, and Rocky Mountain 
 spotted fever are still in hiding, although the 
 Typhus Research Commission of the League of Red 
 Cross Societies to Poland reports substantial progress 
 in investigating the cause of typhus. 1 
 
 1 See Journal of the American Medical Association, page 1054, 
 April 8, 1922. 
 
 25
 
 26 Forty Notifiable Diseases 
 
 The parasite of plague is a vegetable organism, 
 a bacillus; the parasite of malaria is an animal organ- 
 ism; and the parasite of yellow fever, according to its 
 discoverer, Noguchi, may be described as "betwixt 
 and between" a vegetable and an animal. The para- 
 sites of dengue, typhus fever, and Rocky Mountain 
 spotted fever are, as above indicated, unknown. 
 
 The malarial parasites are transmitted by mos- 
 quitoes of the genus Anopheles; and both the yellow 
 fever and the dengue parasites are transmitted by 
 the species of mosquito known as JEdes calopus. 
 There are some 50 different species of Anopheles 
 known. However, not all of them transmit malaria. 
 The JEdes calopus is the same mosquito that we 
 used to call the Stegomyia calopus, and before that 
 we called him 1 the Stegomyia fasciata, and still before 
 that, at the time Walter Reed caught him red-handed 
 in the act of transmitting yellow fever, he was the 
 Culex fasciata. In fact, if you were to chase him 
 back through all his names, you would find he has 
 been christened no fewer than seventeen or eighteen 
 times. Such a wholesale renaming process usually 
 comes about through the fact that from time to 
 time different persons in different parts of the world 
 describe and name a species, and later it is found 
 that these names all mean the same thing; then, 
 by agreement, the oldest name sticks. 
 
 Considering the malarial parasite a little more in 
 del ail, it will be noted that the mosquito is host 
 
 1 In personifying the mosquito, the masculine pronoun is used 
 here, although it should be understood that it is really the female 
 that actually transmits the disease; the male never bites a person.
 
 Diseases Spread by Insects 27 
 
 for this parasite, and that the human being is host 
 for both the malarial parasite and the mosquito. 
 
 The malarial parasite reproduces in the blood of 
 the human being; it also reproduces in the body 
 of the mosquito. In the human being it reproduces 
 without sex, but in the mosquito there is a mating 
 process; that is, the reproduction is sexual. The 
 host in which sexual reproduction takes place is 
 known as the definitive host, and the one in which 
 non-sexual reproduction takes place is known as 
 the intermediate host. Accordingly, the human being 
 is the intermediate host and the mosquito the defini- 
 tive host for the malarial parasite. 
 
 In theory it is possible to control any of these 
 team-work diseases by breaking up the team; that 
 is, by controlling either member of it the malarial 
 parasite or the mosquito; the plague bacillus, the 
 rat, or the flea; the typhus germ or the louse. 
 
 In practice we sometimes attack in one place 
 and sometimes in another. We may try to break 
 up the germ-mosquito combination by killing the 
 germ or by killing the mosquito. When we try to 
 control malaria by the broadcast use of quinine, as 
 is being done in an experiment in Sunflower County, 
 Mississippi, we are making our attack on the germ. 
 When we try to control it by drainage or oiling, 
 we are attacking the mosquito. 
 
 In combating plague, it has been found most 
 practicable to attack the germ-flea-rat combine by 
 killing the rat. That is why an anti-plague cam- 
 paign consists of rat killing.
 
 28 Forty Notifiable Diseases 
 
 In typhus fever, the germ-louse combine is broken 
 up by killing the louse - "delousing," as the process 
 is called. 
 
 In dengue and yellow fever the attack is made 
 on the mosquito. 
 
 Rocky Mountain spotted fever, as above indicated, 
 is transmitted by the tick, 1 Dermacenlor andersoni. 
 
 Back in 1906 Ricketts discovered how this fever 
 is transmitted. Not only adult ticks, both male and 
 female, but also larvae and nymphs, are capable of 
 transmitting the disease, and the eggs from infected 
 ticks in turn hatch out infected larvae. 
 
 The natural reservoir of the infection seems to 
 be the wild animals in the region where the fever 
 occurs. Ticks feeding on these get the infection and 
 transmit it to man. The great mass of ticks unques- 
 tionably become engorged on domestic animals, and 
 this suggests dipping and spraying as means of tick 
 control. Sheep grazing diminishes the number of 
 ticks, "for the reason that ticks die upon sheep, 
 and many of the engorged females are not fertilized 
 on account of the difficulty experienced by the 
 males in propelling themselves through the thick 
 wool in search of the females. This method has 
 been successfully tried in controlling the ticks and 
 the disease in the Bitter Root Valley in 1914." 
 
 1 Although the tick is not a true insect, it is classed with the 
 other true insects that are involved in this group of diseases.
 
 CHAPTER SEVEN 
 
 THE VENEREAL DISEASES 
 
 Chancroid Gonorrhea Syphilis 
 
 THE principal facts to be learned in connection 
 with these diseases may perhaps be best studied by 
 referring to the table on the following page. 
 
 One of the greatest difficulties in trying to check 
 the spread of venereal diseases is that in many 
 instances the patient, believing he has fully recovered, 
 is still a carrier of the germs. A person having gonor- 
 rhea, for example, may apparently get well, while 
 still harboring the germs. In this condition, though 
 seemingly well himself, he can transmit the infection 
 to others. Thus wives sometimes become infected 
 from husbands who have supposed themselves 
 recovered from the disease. 
 
 In connection with these facts it may be said 
 here that one of the greatest causes of the spread 
 of disease may be found in the fact that many 
 persons, directly or indirectly, transmit a disease 
 without realizing it. The disease-spreading Typhoid 
 Mary (page 19) well illustrates this point. It occa- 
 sionally happens that such unwitting spread of 
 disease brings about civil action on the part of the 
 victim. An interesting example of this sort occurred 
 a few years ago. A man sued one of our largest 
 railroads for $10,000 damages. He and his family 
 had contracted smallpox from a section gang on the 
 railroad, and the railroad, it was held, was liable for 
 damages, by allowing the disease to be transmitted. 
 
 29
 
 30 
 
 Forty Notifiable Diseases 
 
 TABLE 3 
 
 Acquired by sexual contact X 
 
 Occasionally by accident 
 
 Never hereditary 
 
 May be acquired from either parent at time of conception 
 
 May be acquired from mother at any time during ges- 
 tation 
 
 May be acquired from mother at time of delivery ' . . . 
 
 Local (limited, usually to genitalia) X 
 
 General 
 
 Begins local but may reach remote parts, as bladder, ure- 
 ters, kidneys, seminal vesicles, testes, or even joints, 
 causing what is known as "gonorrhenl rheumatism" . 
 
 Causing acute pain X 
 
 Causing much blindness 
 
 Causing many operations on women 
 
 Causing insanity 
 
 Causing most sterility in both sexes 
 
 Causing most stillbirths 
 
 Causing most varied symptoms, as eruptions, r.orvoi; 
 manifestations 
 
 Most prevalent 
 
 Relative prevalence in the United States 2 
 
 Always curable but more or less disfiguration X 
 
 Curable when taken in hand early (?) . . 
 
 Occasionally totally refractory to treatment 
 
 Apparently cured, really cured X 
 
 Apparently cured, yet more or less doubtful for a long 
 time 
 
 Treatment by cauterization X 
 
 Treatment by general measures and antiseptics . . . 
 
 Treatment by general measures, mercury, and salvarsan 
 (606) ' 
 
 1 In this case it develops in the eyes of the infant and is known 
 as ophthalmia neonatorum. Much blindness is directly due to this 
 cause, but such blindness could be easily prevented by dropping 
 1 per cent solution of silver nitrate in the eyes of the new-born child.
 
 The Venereal Diseases 31 
 
 He who transmits a venereal disease, however, 
 inflicts a far greater damage than the railroad did, 
 and in many cases he does it (or rather takes the 
 chance) knowingly, whereas the railroad did this 
 unwittingly. Would not the transmission of venereal 
 disease be cause for civil action? Will the trans- 
 mission of venereal disease ever be cause for criminal 
 action? 
 
 Early in 1922 a bill was introduced into the 
 Reichstag providing, among other things, that "any 
 one who knows, or to judge from his condition must 
 assume, that he is suffering from an infectious sexual 
 disease, and who, in spite of the fact, exposes another 
 in the customary manner to the danger of infection, 
 is subject to imprisonment."
 
 CHAPTER EIGHT 
 
 DISEASES AFFECTING ESPECIALLY THE NERVOUS 
 SYSTEM 
 
 Cerebrospinal meningitis Tetanus 
 
 Poliomyelitis (infantile paralysis) Encephalitis 
 Rabies 
 
 THESE five diseases affect especially the brain 
 and spinal cord. Of the five, rabies, tetanus, and 
 encephalitis are considered elsewhere (see Glossary) ; 
 cerebrospinal meningitis and infantile paralysis will 
 be discussed briefly in this chapter. 
 
 The germ that causes cerebrospinal meningitis has 
 been known a long time, but the one that causes 
 infantile paralysis has only lately been isolated by 
 Flexner and Noguchi of the Rockefeller Institute, 
 New York. 
 
 Cerebrospinal meningitis (cerebrospinal fever, or 
 "spotted fever," if you choose) is an epidemic dis- 
 ease of some importance, causing about six or seven 
 thousand deaths a year. In addition to the deaths 
 that it causes, a large number of the victims are 
 left permanent cripples of one kind or another. 
 
 The epidemic behavior of the disease is rather 
 peculiar, 1 and in this respect there is only one other 
 disease infantile paralysis like it. In 1904 an 
 outbreak occurred in Madison, Florida, which illus- 
 
 1 The explanation that is offered for such erratic lx;havior is 
 that there is a large number of carriers among the well, and that 
 of those exposed, only a very few ever contract the disease. Although 
 admittedly lame, this is the best explanation we have to olFer at 
 the present time. 
 
 32
 
 Diseases of Nervous System 33 
 
 trates this behavior. Suddenly, like a bolt from a 
 clear sky, a case of the disease appeared, and then 
 another, and another; then a death occurred, and 
 another, and another. Excitement ran high. In all 
 there were 30 cases diagnosed, and 7 deaths. 
 
 Now, one of the notable facts concerning this 
 outbreak is that in only two instances did more 
 than one case occur in a family, or indeed in the 
 same household; and in one of these two instances 
 both cases appeared on the same day. This is not 
 an uncommon phenomenon in the epidemic behavior 
 of both cerebrospinal fever and infantile paralysis. 
 
 Another notable phase of the outbreak is that 
 the epidemic rose like a tide and then subsided, 
 leaving nothing to show that it had been there 
 except the deaths and the fact that one of the 
 individuals who recovered was afterward cross-eyed. 
 
 Another fact to be noted is that while this outbreak 
 was going on in Madison, there was, 6 miles away 
 in the country, a little girl who had the disease, 
 although she had not been to Madison for half a 
 year; also, there was another case 12 miles in another 
 direction; there were two more over 100 miles away 
 in Columbia County; and about 200 miles away in 
 Marion County there was still another one. But the 
 center of the storm was at Madison. 
 
 Now, in a general way, this is what happens in 
 most outbreaks of meningitis. There is a center 
 where the disease reaches its maximum of intensity; 
 but sprinkled round at varying distances and with 
 no seeming connection there are a few other cases.
 
 34 Forty Notifiable Diseases 
 
 Infantile paralysis behaves in the same way. We 
 may go for years without a case; then without warn- 
 ing there is an outbreak. There is always a focus 
 more intense than elsewhere, and radiating out from 
 that focus other cases are encountered in varying 
 numbers. 
 
 Infantile paralysis does not cause so many deaths 
 as it does permanent cripples. Certain nerves in 
 the spinal cord become paralyzed, and then the mus- 
 cles presided over by these nerves become para- 
 lyzed. The disease often comes on suddenly. A child 
 may be quite well, to all appearances, and then per- 
 haps miss a meal and possibly have a little fever 
 for a day or so; then it is soon noticed that the 
 child does not use, say, a foot, or leg, or arm so 
 insidious is the disease.
 
 CHAPTER NINE 
 
 DISEASES CONTRACTED FROM LOWER ANIMALS 
 
 Actinomycosis Rabies 
 
 Anthrax Rocky Mountain spotted 
 
 Glanders fever 
 
 Plague Trichinosis 
 
 OF these seven diseases, only rabies will be con- 
 sidered here. Information regarding the other six 
 diseases, and also additional information on rabies, 
 may be had by referring to the Glossary. 
 
 Rabies, or hydrophobia, is a disease to which 
 probably all warm-blooded animals are susceptible. 
 Dogs chiefly get it, but less often cats, cows, horses, 
 and other domestic animals. It sometimes gets 
 started among wild animals, as wolves, and plays 
 havoc with them. 
 
 The germ causing the disease is not known, but 
 it is known that the brain and spinal cord are the 
 parts chiefly attacked. An Italian by the name of 
 Negri found in the brain and spinal cord of animals 
 affected with rabies certain little bodies, since known 
 as "Negri bodies." These we know are connected 
 in some way with rabies; indeed, they may be the 
 germs themselves. They have been found in the 
 brain, spinal cord, and saliva of animals affected 
 with rabies, but nowhere else. The disease is trans- 
 mitted through the bite of an infected animal. 
 
 When a dog's head is sent to the laboratory to 
 be examined for rabies, it is these little "Negri 
 bodies" that are hunted out. If the bacteriologist 
 
 35
 
 36 Forty Notifiable Diseases 
 
 finds them, he reports back that the animal had 
 rabies. But sometimes he cannot find them; then 
 he does not know whether the animal had rabies 
 or not, for it should be understood that these Negri 
 bodies are very scarce the first day or so after the 
 disease develops. The bacteriologist might hunt for 
 hours and hours and still not find them. But as 
 the disease progresses in the animal, the bodies 
 become more and more abundant, and by the time 
 death takes place they are usually numerous and 
 easy to find. 
 
 Thus it is apparent that if tJie bacteriologist fails 
 to find the Negri bodies, he cannot pronounce the animal 
 free from the disease. 
 
 The practical lesson to be learned from these 
 facts is that when an animal is suspected of having 
 rabies, do not kill him, but shut him up and wait. 
 He is your best witness. If you kill your witness 
 and then the laboratory fails to find the Negri 
 bodies, you will never know whether the animal 
 was mad or not. Shut him up instead, and if he 
 has rabies he will get rapidly worse and will die 
 in 4 or 5 days with unmistakable symptoms. You 
 will then know what you are dealing with.
 
 CHAPTER TEN 
 
 DISEASES HAVING A WELL-DEFINED GEOGRAPHICAL 
 LIMITATION 
 
 Malaria Hookworms Rocky Mountain spotted fever 
 
 IF you were to draw a line through a map of the 
 United States from top to bottom at about the 
 middle of the map, and then another line from 
 right to left at about the middle, the area would 
 be blocked out in four quadrants northeast, south- 
 east, northwest, and southwest. The southeast quad- 
 rant is the area of endemic malaria in the United 
 States. Except for a little territory in New York 
 and New Jersey, and another small area in California, 
 malaria is limited to the southeast quadrant. Why? 
 Why is it not found in Maine, or Minnesota, or 
 Colorado? The answer is not far to seek. In Maine 
 there is enough rain, but it is too cold. In Minnesota 
 there is also rain, but it likewise is cold. In Colorado 
 it is warm enough, but there is not much rain. 
 
 Two conditions for malaria are required: water in 
 which mosquitoes can breed and a reasonable warmth. 
 In the southeast quadrant those conditions are 
 fulfilled. It is the one quarter of the United States 
 that has an abundance of both warmth and moisture. 
 In the Sacramento and San Joaquin valleys there 
 is enough moisture to provide a mosquito fauna, 
 and, as is to be expected, there is malaria. 
 
 Centering around New York and New Jersey is 
 an area more or less famous for mosquitoes. One 
 would naturally expect an area of malaria there. 
 
 37
 
 38 Forty Notifiable Diseases 
 
 Regarding this area, the United States Public Health 
 Service says: "Of the two smaller endemic areas 
 (of malaria), one includes a section of the northern 
 part of New Jersey, southeastern New York, Connec- 
 ticut, Rhode Island, and part of the state of Massa- 
 chusetts." 
 
 The hookworm is even more sensitive to environ- 
 mental conditions than the malarial mosquito, and 
 is a little more restricted in habitat. Like malaria, 
 the hookworm occupies the southeast quadrant of 
 the United States, and like malaria it has a little 
 patch in California where warmth and moisture 
 prevail. But unlike malaria it has no foothold in 
 New York and New Jersey. The two conditions 
 required for malaria are even more necessary for 
 the propagation of hookworms. 
 
 Such is the distribution of hookworms in the 
 United States. If you want a clear picture of their 
 distribution over the whole world, just imagine a 
 globe with the torrid zone widened out from 47 
 degrees to 80 degrees, and you will have the potential 
 habitat of this parasite. It is true that in this zone 
 there are great stretches of desert where the hook- 
 worm could not exist. Even the highly porous soil 
 of portions of southern Florida dries out so quickly 
 that the hookworm cannot survive. In this great 
 belt there are also mountains that have a mean 
 temperature entirely too low for the hookworms; 
 but in a general way, taking into consideration the 
 exceptions noted, this belt represents the hookworm 
 zone of the world.
 
 Geographical Limitation 39 
 
 The third and last of the forty notifiable diseases 
 that have a geographical limitation is Rocky Moun- 
 tain spotted fever. This disease prevails in the bitter 
 Root Valley of Montana, and to a less extent in 
 the neighboring states of Idaho, Wyoming, California, 
 and Washington. 
 
 It will be recalled that it is transmitted by ticks, 
 of the species Dermacentor andersoni. These ticks 
 infest both the wild and the domesticated animals 
 in this region, and occasionally they get the infection 
 from some of these animals and in turn may transmit 
 it to man. The parasite itself is unknown. 
 
 Maver has shown by experiment that other kinds 
 of ticks may also become carriers of the disease. 
 He found that ticks collected in three widely sepa- 
 rated states Utah, Missouri, and Massachusetts 
 were capable of transmitting the infection. There 
 is, therefore, no apparent reason why the parasite 
 should occupy such a limited area as it does at 
 present. In time it may come to occupy a larger 
 orie no one can say.
 
 CHAPTER ELEVEN 
 
 DISEASES OF UNKNOWN CAUSATION 
 
 Cancer Pellagra 
 
 BESIDES cancer and pellagra there are many other 
 diseases, the cause of which is unknown. We do 
 not know, for example, the cause of measles, whoop- 
 ing-cough, or smallpox; but although the germ 
 causing these diseases is unknown, we are neverthe- 
 less sure that they are germ diseases. On the other 
 hand, cancer is not even suspected of being caused 
 by a germ; pellagra is thought to be of dietary 
 origin, but there is no certainty about the cause 
 of either of them. 
 
 As cancer is by far the more important of the 
 two diseases listed at the head of this chapter, we 
 shall devote most of our time to a consideration of 
 it. A few facts concerning the disease may be learned 
 by referring to page 65. 
 
 Cancer is a much more important disease than 
 the majority of people generally think it to be. A 
 comparison with some of the other diseases will 
 show its importance. Turning to the table on page 
 11 listing the forty notifiable diseases in the order 
 of the number of deaths that they cause, we note 
 that the four leading causes in 1917 were tuberculosis, 
 pneumonia, cancer, and influenza. It will be observed 
 that the first three diseases cause 60,000 deaths, or 
 over, in a year; and then for the fourth disease 
 there is a sudden drop to one fifth that number. 
 Cancer accordingly stands third highest among 
 these causes of deaths. 
 
 40
 
 Diseases of Unknown Causation 41 
 
 It has been found that the number of deaths from 
 cancer is increasing. The number of deaths from 
 pneumonia is also increasing, but at a less rapid 
 rate. Thus, if the present rate keeps up, within a 
 measurable time cancer will take its place as the 
 leading cause of death in the United States. 
 
 Women are affected much more than men. It is 
 easy to remember that the death rate from cancer 
 among women is 1^ times that among men. 
 
 Cancer is essentially a disease of advancing years. 
 Over ten times as many cases occur above the age 
 of 45 as below it. 
 
 What every one wants to know is whether cancer 
 is hereditary, or as the laymen are learning to frame 
 the question now, whether a "predisposition to 
 cancer" is hereditary. The subject has been investi- 
 gated by the Medico-Actuarial Committee, and their 
 findings are of interest. The Committee studied a 
 group of persons with a history of two or more 
 cases of cancer in the family. The expected death 
 rate in this group was 87.3. The actual death rate 
 proved to be only 69, and of these only 4 were from 
 cancer. 
 
 In 1914 there was formed in New York City the 
 American Society for the Control of Cancer. Dr. 
 Frederick L. Hoffman, of the Prudential Insurance 
 Company of America, is and has been a leading 
 spirit in that organization. The Society has issued 
 a leaflet under the caption, "Vital Facts about 
 Cancer." The following excerpts are from that 
 leaflet:
 
 42 Forty Notifiable Diseases 
 
 "During the Great War the United States lost 
 about 80,000 soldiers. During the same two years 
 180,000 people died of cancer in this country. Cancer 
 is now killing one out of every ten persons over 
 40 years of age. 
 
 "Many of these deaths are preventable, since 
 cancer is frequently curable, if recognized and prop- 
 erly treated in its early stages. 
 
 "Cancer begins as a small local growth which 
 can often be entirely removed by competent surgical 
 treatment, or, in certain external forms, by using 
 radium, the X-ray, or other methods. 
 
 "Cancer is not a constitutional or 'blood' disease; 
 there should be no thought of disgrace or of 'heredi- 
 tary taint' about it. 
 
 "Cancer is not a communicable disease. It is not 
 possible to 'catch' cancer from one who has it. 
 
 "Cancer is not inherited. It is not certain even 
 that a tendency to the disease is inherited. Cancer 
 is so frequent that simply by the law of chance 
 there may be many cases in some families, and this 
 gives rise to much needless worry about inheriting 
 the disease. 
 
 "The beginning of cancer is usually painless; for 
 this reason its insidious onset is frequently overlooked 
 and is too easily neglected. Other danger signals 
 must be recognized and competent medical advice 
 obtained at once." 
 
 Then the authors enumerate some of the signals: 
 
 Lump in the breast. "Every persistent lump in 
 the breast is a warning sign. All such lumps are
 
 Diseases of Unknown Causation 43 
 
 by no means cancer, but even innocent tumors of 
 the breast may turn into cancer if neglected." 
 
 Discharge or bleeding. "In women, continued un- 
 usual discharge or bleeding requires the immediate 
 advice of a competent doctor. The normal change 
 of life is not accompanied by increasing flowing, 
 which is always suspicious. ..." 
 
 Sore that does not heal. "Any sore that does not 
 heal, particularly about the mouth, lips, or tongue, 
 is a danger signal. Picking or irritating such sores, 
 cracks, liberations, etc., or by treating these skin 
 conditions with home remedies, pastes, poultices, 
 caustics, etc., is playing with fire. Warty growths, 
 moles, or other birthmarks, especially those subject 
 to constant irritation, should be attended to imme- 
 diately if they change in color or appearance or 
 start to grow." 
 
 Indigestion. "Persistent indigestion in middle 
 life, with loss of weight and change of color, or 
 with pain, vomiting, or diarrhea, call for thorough 
 and competent medical advice as to the possibility 
 of internal cancer." 
 
 As to pellagra, there is not much to be said. Its 
 exact cause is not known. Some theories about it 
 may be mentioned. 
 
 The "spoiled maize" (cornbread) theory, first 
 proposed by Lombroso, a great Italian scholar. 
 This theory is now generally abandoned. 
 The "sandfly" theory, proposed by Sambon, 
 an Englishman. Sambon thought the epidemio- 
 logical evidence sufficient to convict the sandfly
 
 44 Forty Notifiable Diseases 
 
 of transmitting the disease. This theory also 
 
 is now abandoned. 
 
 Other minor theories have been proposed, but we 
 are not interested in them. At present the prevailing 
 opinion is that the disease has some connection with 
 the diet. Certain it is that treatment addressed to 
 correction of all errors of diet has been the most suc- 
 cessful. It is well to remember that pellagra has 
 three groups of symptoms: 
 
 1. Nervous symptoms, which may consist of 
 anything from hot or cold sensations on the 
 one hand, to insanity at the other extreme. 
 
 2. Intestinal symptoms. 
 
 3. Eruption. 
 
 In a given case any of these symptoms may be 
 partly or wholly suppressed.
 
 CHAPTER TWELVE 
 
 SOME DISEASES WHICH MAY BE SPREAD BY 
 CARRIERS 
 
 Diphtheria Paratyphoid 
 
 Gonorrhea Pneumonia 
 
 Influenza Poliomyelitis 
 
 Malaria Syphilis 
 
 Meningitis Typhoid 
 
 WHEN a person gets well from a communicable 
 disease, he usually gets rid of the germs causing it. 
 This is particularly true in such diseases as measles, 
 whooping-cough, and smallpox. 
 
 But in some other diseases this is not the case at 
 all. In diphtheria, for example, the person may get 
 well and still retain the germs; in other words, he 
 becomes immune to the diphtheria germs, but the 
 germs themselves continue to grow in his throat for 
 weeks or months. Such persons are called "diph- 
 theria carriers." Ehrlich, the great German investi- 
 gator, used to speak of such cases as having "immu- 
 nity without sterilization." 
 
 It should be understood that all cases of diphtheria 
 do not terminate as carriers, but that quite a number 
 do. Moreover, some persons become carriers of 
 diphtheria without ever having had the disease, or 
 at least without knowing that they had it. Such 
 persons might have had a mild attack that went 
 undetected, or may never have had it at all. Never- 
 theless, they are carriers and are capable of trans- 
 mitting the disease to susceptible persons. 
 
 45
 
 46 Forty Notifiable Diseases 
 
 These facts apply with equal force to all the 
 diseases at the head of this chapter. In each case 
 a person may be a distributor of the infection after 
 having had the disease in question, or he may be 
 a distributor even though there is no history of his 
 having had the disease.
 
 CHAPTER THIRTEEN 
 
 DISEASES DUE TO FILTERABLE VIRUSES 
 
 Dengue Scarlet fever (?)i 
 
 Measles Smallpox 
 
 Poliomyelitis Trachoma 
 
 Rabies Yellow fever 
 
 THE word "virus" does not have a very sharply 
 defined meaning. It was formerly applied particu- 
 larly to the germs of smallpox and cowpox. As long 
 as the germ of a communicable disease is unknown, 
 it is commonly referred to as the "virus." 
 
 A "filterable virus" is one that will go through 
 a special filter, made of unglazed porcelain or diato- 
 maceous earth, that filters out ordinary bacteria. 
 There are several kinds of these special filters in 
 the market, as the "Berkefeld" and the "Chamber- 
 land," of which the pores are so fine that while they 
 will let liquid through, they will hold back all ordinary 
 germs one could almost say all known germs. In- 
 deed, one could have said so until recently, but now 
 that Noguchi has discovered the germ of yellow 
 fever, and Flexner and Noguchi together have found 
 the germ of poliomyelitis, exception has to be made 
 of these two. 
 
 1 Not only here, but generally throughout this book, the interroga- 
 tion point implies a degree of doubt. 
 
 47
 
 CHAPTER FOURTEEN 
 
 NINE DISEASES AMENABLE TO IMMUNIZATION 
 
 Asiatic cholera Rabies 
 
 Bubonic plague Smallpox 
 
 Paratyphoid Diphtheria 
 
 Typhoid Tetanus 
 Anthrax 
 
 IT is quite possible to obtain immunity against 
 several of the notifiable diseases. Of the nine listed 
 above, a person can be immunized against the first 
 four Asiatic cholera, bubonic plague, paratyphoid, 
 and typhoid by the injection of a dead culture 
 of the germs causing the disease; for the next three - 
 anthrax, rabies, and smallpox living attenuated 
 organisms are used to obtain immunity; and for the 
 last two diphtheria and tetanus an antitoxin 
 is effective. 
 
 Immunity may be acquired against two of these 
 diseases Asiatic cholera and bubonic plague in 
 more than one way; namely, by the use of dead 
 cultures and by the use of living attenuated organ- 
 isms. But however they may be varied or combined, 
 there are at bottom only the three methods above 
 mentioned of producing artificial immunity. 
 
 The simplest method is by the injection of dead 
 cultures of the germs causing the disease. But 
 before going into that let me give you a theory that 
 has been advanced. This is not accepting it or 
 rejecting it, understand, but merely stating it. 
 According to this theory, living germs of typhoid 
 do riot hurt one it is only after they die and disin- 
 
 48
 
 Diseases Amenable to Immunization 49 
 
 tegrate that the poison which causes the symptoms 
 of the disease is set free. When we have typhoid 
 fever, it is not the living germs but the dead ones that 
 make us sick. Of the living germs in our bodies, 
 some are multiplying, some are dying; but the living 
 ones contribute to the disease only in furnishing more 
 and more germs to die, while in turn the dead ones 
 are the real cause of the trouble. And it is the dead 
 ones that cause the immunity to develop. 
 
 According to this theory, then, when dead typhoid 
 germs are injected into the body, the patient is 
 virtually given a little slice of typhoid fever. These 
 dead germs cause the immunizing substances to 
 appear in the blood, after which the person is immune. 
 For typhoid fever is like smallpox in that a person 
 ordinarily has it only once. 
 
 The typhoid germs that are used in inoculating 
 against the disease are grown in the laboratory, and 
 then killed by heat and a small quantity injected 
 into the individual. After a week to ten days a 
 second dose is given, and then a third. Paratyphoid 
 is prevented in the same way. 
 
 For Asiatic cholera there are two methods of 
 immunization one by the injection of dead germs, 
 as in typhoid, and the other by the use of "attenu- 
 ated" germs, similar to the method used in vaccinat- 
 ing against anthrax, which we shall discuss shortly. 
 
 For plague also there are two methods, with some 
 additional variations. The first and chief method, 
 known as Haffkine's, consists of injections of dead 
 plague germs, just as dead typhoid germs are in-
 
 50 Forty Notifiable Diseases 
 
 jected to immunize against typhoid. A second 
 method that of giving attenuated germs has 
 also been used. The next paragraph will make clear 
 the details of the method of giving attenuated germs. 
 When we turn to anthrax, rabies, and smallpox, 
 we find that immunization is obtained by giving 
 attenuated germs only. In this method the germs 
 are alive, but before they are injected they must 
 be weakened "attenuated," as it is called. Now 
 this method was not learned in a day. Indeed, it 
 required a quarter of a century of study by scientific 
 men to bring the idea to full fruition. Devaine and 
 Rayer, Koch, Delafond, and Jaillard are some of 
 the names that will be forever associated with the 
 history of the anthrax germ. But to Louis Pasteur 
 belongs the honor of having won a complete victory 
 over it. Without going into the various experiments 
 or steps, but merely stating the result, Pasteur found 
 that he could attenuate anthrax germs by growing 
 them in neutral chicken broth at a temperature of 
 42 or 43 degrees (centigrade) in the presence of air. 
 Thus grown they would not form "spores" 1 and 
 would gradually cease to grow and ultimately die; but 
 
 1 "Spores" of germs correspond roughly to the seeds of higher 
 plants. When spore-forming germs (nil germs do not form spores), 
 as the anthrax germs, for example, are grown under certain condi- 
 tions, a tiny body develops in each germ, and then the rest of the 
 germ disappears and only this little body known as the spore 
 is left. It is very resistant to unfavorable conditions. It may remain 
 dormant for years, and then when brought into favorable environ- 
 ments it will revive and begin to grow and reproduce. When Pasteur 
 was working with anthrax it was known that certain pastures were 
 rated as dangerous, for cattle that grazed upon them would sooner 
 or later develop anthrax in the herd. It was customary at that
 
 Diseases Amenable to Immunization 51 
 
 before the cultures were finally dead, they could 
 be injected into susceptible animals and the disease 
 produced in mild form. The animals thus treated 
 were afterward found to be immune to virulent 
 germs. 
 
 It is not customary to immunize human beings 
 against anthrax, but of course it could be done. 
 
 As to rabies, the germ itself is not known and 
 cannot therefore be grown in the laboratory; but 
 Pasteur found that the virus is present in the brain 
 and spinal cord of an animal affected with the dis- 
 ease. The way he proved this was by injecting a 
 small portion of the brain or spinal cord of such 
 an animal into a well animal (which we will call 
 No. 2). For this experiment he used the rabbit by 
 preference. He found that rabbit No. 2 would develop 
 rabies in about 14 days. Then he found that he 
 could inject a small bit of the cord of animal No. 2 
 into a third animal (No. 3) and this would produce 
 rabies in just a little less time than in No. 2; No. 4, 
 he found, would come down in still less time, and 
 when he had passed it through about 50 rabbits, 
 the incubation period was reduced to 6 days. But 
 try as he would he could not reduce the incubation 
 period below 6 days. 
 
 time to bury all animals that died of anthrax. This measure was 
 thought sufficient to rid the herd of the infection. But Pasteur 
 found that above the graves of these buried animals he could isolate 
 these spores from the soil, even years after the animals had been 
 buried and crops had been grown over the grave. But how the 
 spores could get up to the surface from the animal buried 3 to 6 
 feet deep was at first a mystery. Pasteur showed, however, that 
 earthworms brought them up.
 
 52 Forty Notifiable Diseases 
 
 Now, let us see just what happened. By passing 
 the virus through rabbits he increased its virulence; 
 in other words, he made it stronger or, as the bac- 
 teriologists say, "exalted the virus." The more 
 "exalted" the virus, the quicker it will produce 
 death. 
 
 Having "exalted" the virus by passing it through 
 rabbits, Pasteur undertook to "unscramble the 
 eggs"; that is, to weaken the virus or attenuate it. 
 This he succeeded in doing by a method of drying. 
 He took the spinal cord of a rabbit that had died 
 of rabies, and dried it 14 days; then he found that 
 he could inject it into another rabbit and it would 
 not produce rabies at all. The year before this, 
 Pasteur had attenuated anthrax germs by growing 
 them in an unsuitable temperature. Now, he had 
 attenuated rabies virus by drying. 
 
 When Pasteur had attenuated anthrax germs, it 
 was only another step to protecting an animal against 
 anthrax. All he had to do was to inject a few of 
 these attenuated germs, and the animal would have 
 a very mild case of the disease hardly get sick at 
 all; and after that he would be immune to anthrax. 
 But to produce immunity against rabies was not so 
 simple. He knew the virus was safe when it had 
 been dried 14 days. So he began by giving an animal 
 an injection of cord that had been dried 2 weeks. 
 Then the next day he gave an injection that had 
 been dried only 13 days; the dose the next day had 
 been dried 12 days; then 11, 10, 9, 8, and 7, and 
 on down to a perfectly fresh cord that had not been
 
 Diseases Amenable to Immunization 53 
 
 dried. But the rabbit showed no signs of the disease 
 at all! And yet this last dose, you will remember, 
 was a fresh cord that had not been dried one that 
 would ordinarily produce rabies in 6 days! 
 
 This was Pasteur's victory over rabies. He could 
 immunize a person against this dread disease in 
 about 3 weeks. Thus we have what is known today 
 as the "Pasteur treatment." The scheme of injec- 
 tions has been changed somewhat for instance, 
 we do not begin with a 14-day cord but the prin- 
 ciple is unchanged. It is another method of pro- 
 ducing immunity by the use of a living attenuated 
 virus. 
 
 At the time these experiments of Pasteur's were 
 being carried out (about 1875-80) persons had been 
 vaccinated against smallpox for nearly 100 years, 
 but nobody understood it. All that was known was 
 that there was something between smallpox and cow- 
 pox, and that when one had cowpox he became im- 
 mune to smallpox. Edward Jenner, who first vac- 
 cinated with cowpox to prevent smallpox, suspected 
 that cowpox was a modified form of smallpox, but 
 had no evidence to support it. Pasteur's work with 
 anthrax and rabies gave support to the theory, but 
 it was later experiments that brought forth the proof. 
 It has now been shown that one can vaccinate a calf 
 from a smallpox patient, and from that first calf 
 vaccinate a second calf; from the second calf, a third, 
 and so on until after a while a regular strain of 
 vaccine will be produced. Here we have another 
 example of attenuation, but in this case it is brought
 
 54 Forty Notifiable Diseases 
 
 about by passing the virus through the skin of the 
 calf. 
 
 In actual practice, then, we have three methods of 
 attenuation: for anthrax, by growing the germs at 
 a high temperature; for rabies, by drying; and for 
 smallpox, by passing through the skin of the calf. 
 In each case we produce immunity by using the 
 living organism, but in an attenuated form. 
 
 When we come to diphtheria and tetanus we find 
 that immunization is brought about by the injection 
 of antitoxin. This method is known as "passive 
 immunization." To understand this, it is necessary 
 to know something of the production of antitoxin. 
 
 Suppose we wanted to produce some diphtheria 
 antitoxin. We should proceed in the following 
 manner: 
 
 First, we should get some diphtheria germs. We 
 could get these from the throat of any child having 
 diphtheria. Next, we should plant these germs in 
 suitable liquid in the laboratory, and they would 
 increase in numbers until the liquid became a mass 
 of diphtheria germs. Then we should filter the germs 
 out by running the liquid through a fine strainer so 
 fine that the germs could not pass. 
 
 It would now be found that if this liquid were 
 injected into a susceptible animal, it would cause 
 symptoms of diphtheria. Let us see what really 
 happens. While the diphtheria germs were growing 
 in the liquid, they were throwing off the diphtheria 
 poison, and this poison is still in the liquid. Now 
 let us throw away the germs which we have filtered
 
 Diseases Amenable to Immunization 55 
 
 out, for it is the poison thrown off while the diph- 
 theria germs were growing that we are interested in. 
 This poison is called diphtheria toxin. It is the same 
 thing that the germs are throwing off while growing 
 in the throat of a child ill with diphtheria, and it 
 is the absorption of this toxin by the child that makes 
 him sick. 
 
 Having now a supply of this diphtheria toxin, 
 we first inject a little of it into a horse. It makes 
 him slightly sick, but he soon recovers because the 
 dose is small. When he gets well he is given another 
 dose a little larger this time. As soon as he re- 
 covers from this dose, he is given a third, and a 
 fourth, and so on. He is injected now about twice 
 a week for two or three months; the dose of toxin 
 is made larger and larger with each injection, until 
 finally he can take great quantities without being 
 hurt by it. He is immune against diphtheria 
 toxin. 
 
 Now it has been found that if this horse is bled 
 and a little of his blood mixed with diphtheria toxin, 
 the latter is destroyed. If the toxin thus treated is 
 then injected into another horse or into some other 
 animal, it produces no symptoms at ah*. The blood 
 of the immune horse acts on the toxin as water 
 acts on a fire it "puts it out," so to speak. The 
 blood of a horse that has not been injected with 
 this toxin and immunized will not, of course, act 
 in this way; it is only the blood of an immune horse 
 that is effective. This shows that while the horse 
 is being immunized a new something is being added
 
 56 Forty Notifiable Diseases 
 
 to his blood, something that will overcome the 
 diphtheria toxin or poison. 
 
 This new ingredient, it has been found, is thor- 
 oughly mixed with the liquid portion of the blood, 
 for the corpuscles can all be strained out and the 
 serum will still overcome the diphtheria toxin. This 
 new something has been given a name it is called 
 antitoxin because it is against toxin and overcomes it. 
 
 Now bear in mind that the toxin comes from the 
 growing diphtheria germs, and this toxin is injected 
 into a horse again and again until he is immune 
 against it; that is, large quantities can be injected 
 and it will not hurt him. Then in the blood of this 
 immune horse we find antitoxin, the substance that 
 will overcome the toxin. 
 
 The horse is now bled and his serum put up in 
 bottles ready for use. Let us see when and how it 
 is used. Suppose it is suspected that a child has 
 diphtheria. The doctor takes a little "smear" from 
 the child's throat and sends it to the laboratory. 
 This specimen is examined under the microscope, 
 and if diphtheria germs are found, it is known for 
 a certainty that the child has diphtheria. It will 
 be remembered that while the diphtheria germs are 
 growing in the throat they are throwing off diph- 
 theria toxin. It will be remembered also that we 
 got the toxin to immunize the horse by growing these 
 germs in a laboratory and then saving the resultant 
 toxin. When they grow in the throat of a child, 
 they throw off the toxin in the same way. The child 
 absorbs the toxin and it makes him sick just as it
 
 Diseases Amenable to Immunization 57 
 
 would if it were injected into him. If he absorbs 
 very much of this toxin, it makes him very sick. 
 At this juncture if you could destroy some of the 
 toxin that the child is absorbing, he would not be 
 so sick. Just here is where we have use for the 
 antitoxin that was taken from the immune horse. 
 We inject some of this antitoxin into the child; the 
 antitoxin immediately overcomes some of the toxin 
 and the child is better at once. 
 
 What has been said of diphtheria antitoxin applies 
 also to tetanus antitoxin. To make the tetanus anti- 
 toxin, the tetanus germs are grown instead of the 
 diphtheria genus; otherwise the two processes are 
 identical. 
 
 Bear in mind, however, that when the horse is im- 
 munized against diphtheria, he will not produce any 
 kind of antitoxin except diphtheria antitoxin; and that 
 when immunized against tetanus, he will produce only 
 tetanus antitoxin. 
 
 So much for the production of diphtheria and 
 tetanus antitoxins, and how they are used in the 
 treatment of these diseases. There is also another use 
 to which these antitoxins are put, however, and that 
 is to immunize persons against diphtheria or tetanus 
 and thereby prevent the disease. When diphtheria 
 occurs in a family, for example, the child having 
 the disease is given curative (large) doses of antitoxin. 
 That disposed of, attention is then turned to the 
 other children who have been exposed to the disease. 
 The older practice was to give each one of them 
 an immunizing (small) dose, but lately that practice
 
 58 Forty Notifiable Diseases 
 
 is not so common. It is now known that not all 
 children are susceptible to diphtheria, and it would 
 be useless and expensive to give antitoxin to those 
 not susceptible to the disease. There is a test known 
 as the Schick test by which the doctor can tell which 
 children are immune to diphtheria. This test is 
 applied and then antitoxin is given only to those 
 who are susceptible to the disease. 
 
 Likewise when a person develops tetanus, the 
 tetanus antitoxin is given in large doses, but when 
 one merely gets a wound that is likely to be infected 
 by tetanus germs l an immunizing (small) dose of 
 tetanus antitoxin is given to prevent the disease. 
 Immunity that is conferred by an antitoxin is called 
 passive immunity, whereas that conferred by the 
 use of attenuated germs is called active immunity. 
 Passive immunity is not usually so long-lasting as 
 active immunity. ^\ 
 
 1 "In nature the tetanus bacillus has been found by Nicolaier 
 and others to occur in the superficial layers of the soil. The earth 
 of cultivated and manured fields seems to harbor this organism with 
 especial frequency, probably because of its presence in the dejecta 
 of some domestic animals." Hiss AND ZINSSEH.
 
 CHAPTER FIFTEEN 
 INTER-INFLUENCE OF DISEASE 
 
 IT has long been recognized that some diseases 
 exert their own direct influence, and also an indirect 
 influence through some other disease. Hookworms, 
 for example, cause very few deaths, directly. In 
 1918 there were only 29 deaths from hookworms 
 reported in the Registration Area of the United 
 States. But there is little doubt that through its 
 devitalizing influence it does increase the number 
 of deaths from other diseases, such as malaria, 
 typhoid, and tuberculosis. Indeed, from Kofoid's 
 recent study of the influence of hookworms, it 
 now seems certain that they were of great im- 
 portance in increasing the death rate among the 
 soldiers during the World War, and that they also 
 increased in the training camps the sickness rate 
 from measles, laryngitis, tonsillitis, bronchitis, and 
 pneumonia. 
 
 While hookworm and a few other diseases thus 
 indirectly influence to some extent the death rate, 
 it is the respiratory diseases tuberculosis, pneu- 
 monia, and influenza that seem to cause the 
 most trouble in this respect. In 1917 there were, 
 in round numbers, 110,000 deaths from tuberculosis 
 in the Registration Area, 74,000 from pneumonia, 
 and 12,000 from "flu." That was an ordinary year, 
 and not characterized by any special epidemic. 
 Influenza took its place just above measles and 
 whooping-cough in the number of deaths that it 
 
 59
 
 60 Forty Notifiable Diseases 
 
 caused. But in 1918 there was a great epidemic 
 of influenza that spread all over the world. The 
 number of deaths in the Registration Area mounted 
 up from 12,000 to 232,000! This undoubtedly ex- 
 erted a profound influence on the other respiratory 
 diseases. At any rate, tuberculosis mounted up from 
 110,000 in 1917 to 121,000 in 1918! The increase 
 in pneumonia was still more pronounced, the deaths 
 from that disease mounting up from 74,000 in 1917 
 to 167,000 in 1918!
 
 CHAPTER SIXTEEN 
 
 TUBERCULOSIS 
 
 THE books and pamphlets that have been written 
 about tuberculosis would fill a library, but if you 
 were to read such a library through and jot down 
 the really important things, your notes would hardly 
 fill a page. They would read about as follows: 
 Caused by germs known as tubercle bacilli. 
 Germs may attack any part of the body. 
 When they attack the lungs, the disease is called 
 
 "consumption." 
 When they attack glands, as in the neck, it is 
 
 called "scrofula." 
 When they attack the spinal column, it is called 
 
 "Pott's disease." 
 When they attack the hip, it is called "hip-joint 
 
 disease." 
 Abscesses caused by tubercle bacilli are called "cold 
 
 abscesses." 
 
 Consumption is the commonest form of the disease. 
 Time contracted : usually in childhood. 
 Develops into active cases chiefly from 15 to 30 
 
 years of age. 
 Maximum number of deaths occur between 30 
 
 and 39 years of age. After being contracted, it 
 
 lies dormant for a certain period, during which 
 
 time no germs are given off. At this time the 
 
 disease is called a "closed case." 
 Whenever it develops and begins to discharge 
 
 germs, it is called an "open case." 
 
 61
 
 62 Forty Notifiable Diseases 
 
 All cases are closed cases before becoming open. 
 
 Closed cases are not contagious. 
 
 Many closed cases recover without ever becoming 
 
 open. Such recovered cases leave scars in the 
 
 lungs. This fact gives rise to the German 
 
 saying, "Every man has tuberculosis before he 
 
 dies." 
 
 The disease is found in all parts of the world. 
 It causes more deaths than any other one disease. 
 One form of tuberculosis attacks cattle. 
 A form attacks birds, as parrots and chickens. 
 A form attacks fishes. 
 One form even attacks turtles. 
 Tuberculosis of cattle attacks man. 
 Man spreads the germs by coughing them up and 
 
 spitting them out. 
 Cows do not spit, hence the germs are not spread 
 
 in that way. Instead, they are spread by being 
 
 swallowed and passed in the feces. 
 Two ways of preventing the disease: 
 
 1. Prevent the spreading of germs. 
 
 a. From human beings, by hospitalization of 
 
 the sick. Should be done by state. 
 
 b. From cows, by testing all dairy cattle for 
 
 tuberculosis. Should be supervised, at 
 least, by state. 
 
 2. Prevent closed cases from lighting up into 
 
 open cases. Should be done by individual. 
 Best accomplished by general hygienic 
 measures and above all by keeping body 
 weight to approximately normal.
 
 CHAPTER SEVENTEEN 
 THE SO-CALLED MADSTONE 
 
 OF the various superstitions known to the author 
 in connection with any of the diseases discussed, 
 the most pronounced pertain to hydrophobia. One 
 superstition is that hydrophobia is at its worst in 
 dog-days. Another is that if a person is bitten by 
 a dog, and the animal later "goes mad," the person 
 will also go mad. But the most outstanding of 
 these superstitions is that a "madstone" will cure 
 rabies, and because this superstition is so strongly 
 intrenched in the minds of many persons, it will be 
 discussed somewhat in detail. 
 
 Though few know what a madstone is, many 
 believe in its virtues. Every little while one sees 
 in the press reports that a hydrophobia victim has 
 been taken somewhere to have a madstone applied. 
 Near Water Valley, Mississippi, is an old gentleman 
 who has a madstone that I once had the privilege 
 of holding in my hand. It is about the size and 
 shape of a half walnut, with the split side slightly 
 concaved. It is light in weight, entirely unlike a 
 stone, fissured with small cracks, and of an ashen 
 color. With the point of my knife, even at the 
 risk of arousing my host's anxiety, I determined 
 that it was soft enough to flake off. The story goes 
 that the owner's father got it from a deer, killed 
 in the swamps of Arkansas many years ago. The 
 point of the deer's heart, he said, rested in the little 
 depression in the flattened side of the "stone." 
 
 63
 
 64 Forty Notifiable Diseases 
 
 Extolling its virtues, the old man told me that 
 his madstone would cure snake bites as well as the 
 bite of a dog. He had cured many snake bites with 
 it. Asked what kind, he said "chiefly spreading 
 adders." (It should be noted in this connection that 
 the "spreading adder" or "hog-nosed snake" is not 
 poisonous!) He prized the madstone very highly - 
 had even refused $300 for it, he said. His price for 
 applying it for the bite of a dog was $25, but now 
 that other things had gone up so, his price also had 
 gone up to $35. He charged $5 for applying it to 
 a "spreading adder" bite. 
 
 There is another madstone at Jackson, Mississippi, 
 of which I have a photograph, furnished me by the 
 granddaughter of the owner. I have no history of 
 this stone. 
 
 To determine how many people believe in a mad- 
 stone, I have tested about 2000 individuals, and 
 find that 37 per cent of those tested would resort 
 to its use. 
 
 As to what the madstone really is, I could not 
 say certainly; but the one that I saw is, in my 
 opinion, a dried clot of blood. I fancy gall-stones 
 may sometimes function in this reputed r61e. 
 
 I have heard it said that madstones are taken 
 from the stomachs of deer or cows, and are in part 
 an accretion of hairs that get into the stomach when 
 the animal licks itself.
 
 GLOSSARY 
 
 Actinomycosis (ak-tin-o-my-ko'sis). From the Greek, aklin, a 
 "ray," and mukos, a "fungus.' v> The germ of the disease is often 
 called the ray fungus. Common names of the disease: "big-head" 
 and "lumpy-jaw." First observed in cattle. Looks like one or 
 several big abscesses about the head or jaw, only these swellings 
 do not disappear. Affects man very much the same way. Not 
 common. 
 
 Anchylostomiasis (ang-ky-lo-sto-mi'a-sis). (See Hookworm.) 
 Anthrax (an'thrax). From the Greek, anthrax, meaning a "coal" 
 or "boil." A disease of cattle, sheep, goats, and other animals, but 
 occurs also in man. Other common names: "malignant pustule" 
 and "wool-sorter's disease." When man gets it, it is usually from 
 handling wool or hides. Occasionally got from a shaving brush. 
 
 Bacillus (ba-sil'us). Plural, bacilli. A germ shaped like a corncob. 
 Streptobacillus (strep'to-ba-sil-us). A group form of bacilli hi which 
 the members are arranged end to end in a chain. 
 
 Bacteria. Singular, bacterium. (See Germ.) 
 
 Cancer. A disease of unknown origin, causing many deaths, par- 
 ticularly among people past middle life. A cancer cannot be cured 
 but can be removed when not too large or inaccessible, and the 
 wound will heal. If all the cancer tissue is removed, the cancer 
 will not return; but if the slightest bit is left, recurrence is certain. 
 The best way to remove cancer is by operation or by the application 
 of radium, though it is sometimes successfully removed by so-called 
 "cancer paste" (the latter treatment is hazardous, however). Some- 
 times cancers are so located that operation is impossible; in such 
 cases the X-ray or radium is resorted to. (See page 40.) 
 
 Carrier. (See page 45.) 
 
 Chancroid. (See page 29.) 
 
 Chicken-pox. The more technical name is varicella, which is the 
 diminutive of variola, or smallpox. A mild eruptive disease of chil- 
 dren. Very common. Not very important in itself, causing few or 
 no deaths; but mild cases of smallpox are often thought to be chicken- 
 pox, and in this way smallpox epidemics get started. It is therefore 
 thought best to require that chicken-pox be reported to the health 
 authorities. 
 
 Cholera (kol'er-a). From the Greek, kole, meaning "bile." There 
 are three forms of cholera to be reckoned with: 
 
 (a) Cholera infantum, also known as summer complaint. Attacks 
 infants and young children, causing severe abdominal pains, 
 purgation, vomiting, fever, and great prostration. Responsi- 
 65
 
 66 Glossary 
 
 ble for a great many deaths, although not generally considered 
 communicable and not usually notifiable. 
 
 (6) Cholera nostras, commonly known as cholera morbus. Affects 
 adults very much as cholera infantum affects children. Not 
 communicable and not notifiable, except when Asiatic cholera 
 is present. 
 
 (c) Asiatic cholera. Always notifiable. Common in India and 
 other parts of Asia, where it occurs in great epidemics, often 
 causing hundreds of thousands of deaths. There was a great 
 epidemic of it in London in 1854. In Hamburg, Germany, 
 in 1893 there was an epidemic that lasted two months, during 
 which time there were over 17,000 deaths. Asiatic cholera 
 is due to a minute vegetable organism, the spirillum (see 
 page 8) of Asiatic cholera. The great epidemics of this dis- 
 ease are usually due to the fact that the drinking-water sup- 
 plying large communities in some way becomes contaminated 
 with sewage. 
 
 Hogs have cholera, and so do chickens, but these forms of the 
 disease are entirely different from the disease affecting man. (See 
 page 16.) 
 
 Coccus (kok'us). Plural, cocci. A spherical bacterium. Diplococcus 
 (dip'lo-kok-us). A group form of cocci, arranged in twos. Gonorrhea, 
 meningitis, and pneumonia are caused by diplococci known as "gono- 
 cocci," "meningococci," and "pneumococci," respectively. Slaphylo- 
 coccus (staf'il-o-kok-us). A group of germs that arrange themselves 
 in clusters like a bunch of grapes. Streptococcus (strep'to-kok-us). 
 A group of germs that arrange themselves in a chain, like a string 
 of beads. 
 
 Continued fever. Not a disease in itself. When a doctor cannot 
 tell whether a given case is typhoid, or malaria, or something else, 
 arid the disease hangs on for 7 days, it is reported as "continued 
 fever." 
 
 Dengue (den'gay). Also called "break-bone fever." Patients 
 describe the symptoms as feeling "as if every bone in the body were 
 breaking." In the Southern states it occasionally occurs in epidemics. 
 Persons rarely perhaps never die from it. In former times when 
 yellow fever used to break out every few years, and the fear of it 
 was hanging over the South, an outbreak of dengue was looked upon 
 with very great suspicion lest it should prove to be yellow fever. 
 It is now agreed that dengue is transmitted by mosquitoes, and 
 by the same kind of mosquito that transmits yellow fever, the species 
 known as /Edes calopus. 
 
 Diphtheria (dif-the'ri-a). From the Greek, diphihera, "skin" or 
 "membrane." An acute disease, very contagious. Formerly called
 
 Glossary 67 
 
 in some sections "choking complaint," because of the severity of 
 the throat symptoms. Caused by little rod-like germs in the throat. 
 (See page 45.) 
 Dysentery (dis'-en-ter-e). There are two kinds of dysentery: 
 
 (a) Amebic dysentery. Caused by very minute animal organisms 
 in the intestines. This kind is chronic, sometimes lasting for 
 years; persons who have it are liable to develop abscess of 
 the liver. (See page 16.) 
 
 (b) Bacillary dysentery. Caused by a bacillus in the intestines. 
 
 Encephalitis (en-sef-a-li'tis). From the Greek, kephale, "head," 
 combined with itis, which means an inflammation. A febrile disease 
 (that is, involving a fever), the locus of which is the brain. Causes 
 a variety of nervous symptoms, such as prolonged sleep or drowsiness, 
 excessive talking or laughing. 
 
 Epidemiology (ep-i-dem-i-ol'o-gy). A knowledge made up of all 
 the facts that deal with epidemics. The spread of communicable 
 disease is conditioned by many and varied factors. A milk-borne 
 epidemic of typhoid fever, for instance, would follow the milk route 
 of the offending dairy, while a water-borne outbreak would be dis- 
 tributed wherever the infected water was used. Malaria, on the 
 other hand, being mosquito-borne, would have an entirely different 
 set of limiting factors, hookworms would have still another, smallpox 
 another, and so on. Epidemiology has to do with all these factors. 
 
 Favus. From the Latin, favus, "honeycomb." One of the "ring- 
 worms." Forms crisp, yellowish, cup-like crusts on the scalp. Rare 
 in this country, but more common among certain classes in Europe. 
 Of enough seriousness to bring it within the notifiable class, and 
 when found among immigrants it is cause for exclusion. 
 
 There are several other forms of ringworm, which although not 
 notifiable are common and of more consequence than is generally 
 supposed. 
 
 German measles. Also called rubeola and roseola. A mild eruptive 
 disease, bearing about the same relation to measles that chicken-pox 
 does to smallpox. 
 
 Germ. (See page 3.) The quotations from Hill, below, sum up 
 three of the more important facts concerning germs: 
 
 "Germs of all kinds are simply tiny plants (or animals); some 
 spherical, some more or less sausage-shaped. . . . 
 
 "Germs of any kind never 'evolve' from dirt. They, like other 
 plants (or animals), come only from predecessors. . . . 
 
 "Many different kinds of germs that do not produce disease 
 flourish on or in our skins, noses, mouths, and intestines all the time."
 
 68 Glossary 
 
 Glanders. A very contagious disease of horses and particularly 
 of mules, in which it is usually acute and rapidly fatal. It is com- 
 municable to man. When a case of glanders occurs at any place 
 in the state, the matter is at once reported to the Live Stock Sanitary 
 Commission of that state; or if the state has no commission, it is 
 reported to the State Board of Health and to the Bureau of Animal 
 Industry in Washington. Steps are at once taken to stamp it out. 
 In 1907 an outbreak occurred in Cook's Stables, Jacksonville, 
 Florida. Some 80 horses and mules were found to have the disease. 
 They were taken out to the woods, a great trench dug, and the 
 animals were killed and piled in the trench, covered with lime, and 
 buried. For those who want to know the rest of the story, it might 
 be added that when the next session of the Florida legislature met, 
 Mr. Cook had a bill introduced through which he hoped to obtain 
 payment for the loss of the animals. His argument was that he had 
 killed them to keep the disease from spreading, and in that way 
 had protected the rest of the state. The counter argument was that 
 the horses were sick and dying, and were of no value, hence the 
 state should not reimburse him, even in part. This incident illus- 
 trates the seriousness of an epidemic of glanders when once it gets 
 started. 
 
 Hookworm disease. Caused by small worms (the so-called "hook- 
 worms") in the intestine. Several animals also have hookworms, 
 as the dog and the cat; but these hookworms are not all alike, each 
 kind of animal having its own kind of hookworm. Man has two 
 kinds, known respectively as the Old World hookworms and the New 
 World hookworms, or the European and the American. (See page 38.) 
 
 The hookworms of man inhabit a zone that belts the earth between 
 an irregular line at about 40 degrees North latitude and a similar 
 line about 40 degrees South latitude. Persons living in this zone 
 are more or less liable to get the infection. 
 
 There can be no spread of liookworm disease except through soil 
 pollution. (See page 16.) 
 
 Immunity. W : hen a person is spoken of as being immune against 
 a disease, it means that he will not take it however much he may 
 be exposed. For example, when a person is vaccinated against small- 
 pox he becomes immune against that disease and will not take it. 
 There are certain diseases, however, to which man is not susceptible. 
 Chicken cholera is one of these. Man's relation to such diseases 
 is spoken of as natural immunity. When one is immunized against 
 a disease by vaccination, or by having the disease, that condition 
 is called acquired immunity. 
 
 Incubation period. That period of time between the exposure to 
 a disease and the onset.
 
 Glossary 69 
 
 Influenza. One of the acute infectious diseases which in a most 
 malignant form assumed world-wide proportions during the World 
 War. The very high death rate was due to the large proportion 
 of cases that developed pneumonia. 
 
 Leprosy. The points to remember about leprosy are that it is 
 caused by "germs," which are known as the lepra bacilli; that it 
 is accordingly contagious, but so mildly so that people may some- 
 times live with it for years without ever contracting it; that it is 
 not hereditary; that it is not white, as many suppose; that it is a 
 slow chronic disease, often lasting 15 or 20 years; and that there 
 are some 200,000 cases in the world. Most of these cases are in 
 the Far East about half of them in India and China. There 
 are five or six thousand cases in the Philippines. In 1909 there 
 was an International Leper Congress held at Bergen, Norway. At 
 that time 135 cases were reported from the United States. These 
 were distributed in various centers, the largest of which was in 
 Louisiana. There were some 40 cases in this center. Other centers 
 were at Key West, Florida, and in Minnesota, California, and 
 Massachusetts; the rest were distributed here and there over the 
 country. The United States has lately taken over the leper sana- 
 torium in Louisiana, so that lepers from any part of the United 
 States may now be taken care of there. 
 
 An interesting light on the disease comes from Hawaii. There 
 are two schools in Honolulu for the non-leprous children born of 
 leprous parents. All the lepers in Hawaii are sent to the Island 
 of Molokai, where there is quite a large and happy colony of them. 
 Whenever a child is born there of leprous parents, it is immediately 
 taken back to Honolulu and put in one of these schools for such 
 children. There are about 40 boys in one school and about as many 
 girls in the other, and yet not one of these children has ever devel- 
 oped leprosy. 
 
 Malaria. The outstanding facts about malaria are: 
 
 (a) It is transmitted by mosquitoes and in that way only. People 
 do not get it from swamps or from night air, or from eating 
 muscadines, or late watermelons, or from eating anything 
 else it is got from mosquitoes only. 
 
 (b) Mosquitoes likewise do not get it from swamps, or night air, 
 or from eating muscadines or late watermelons they get it 
 from man, and from man only. 
 
 (c) Only certain kinds of mosquitoes can transmit it those 
 known as Anopheles. 
 
 (d) An Anopheles cannot transmit it until he bites some person 
 who has it gets "loaded," so to speak. A loaded Anopheles 
 can give malaria; one that is not loaded cannot.
 
 70 Glossary 
 
 (e) The protection of the patient from the bite of Anopheles during 
 the whole term that he is a carrier also protects the public round 
 about him. 
 
 (/) Chills and fever may usually be taken to be malaria. 
 
 (g) A person having had malaria for some time may still carry 
 in his blood the germs of malaria after the chills and fever 
 have stopped. In that case he is called a "malaria carrier." 
 Although he himself is well, or relatively so, if a mosquito of the 
 right kind bites him the mosquito will get the germs and then 
 pass them on to some one else. It is important, therefore, 
 to treat malaria or "chills and fever" very vigorously, and 
 to get the patient well as soon as possible so that he will 
 not become a carrier. 
 
 (h) It is not the cause of every obscure ache and pain that human 
 flesh is heir to. 
 
 (i) Quinine is the basis of all malaria treatment. As the late 
 Dr. Eugene Foster used to say, in the treatment of malaria 
 use quinine "internally, externally, and eternally." 
 
 Measles. One of the eruptive fevers. Causes relatively few deaths 
 in itself, but during the disease pneumonia not infrequently develops 
 and ends disastrously. "Big" measles and "little" measles mean 
 the same thing. "Black" measles is also the same disease but in 
 a very aggravated form. The black feature is due to the rupture 
 of small blood vessels and consequent bleeding under the skin. This 
 may also occur in other diseases, as smallpox, scarlet fever, and 
 meningitis. There was a terrible outbreak of disease in London in 
 1666, known as the "Black Plague." It was probably one of these 
 diseases just mentioned possibly smallpox. 
 
 Meningitis (men-in-ji'tis). Also known as "cerebrospinal fever" 
 or "spotted fever." Occurs in epidemics, which are more or loss 
 local. Regarded as contagious. Called spotted fever because some 
 of the cases have hemorrhages under the skin, making durk spots. 
 After a person gets over a severe case, he is still likely to have some 
 of its effects. Patients are often left cripples. One young man of 
 the author's acquaintance was left cross-eyed. 
 
 Microbe. Another name for germ. (See Germ; also page 3.) 
 
 Mumps. An acute disease of the parotid and salivary glands, 
 which swell and become extremely painful. The disease does not 
 last very long 3 or 4 days to a week. It sometimes affects the 
 generative organs of both male and female; in that case it is a dan- 
 gerous malady. 
 
 Paratyphoid. Much like typhoid fever; the difference is more 
 in the germ than in the disease. (See page 16).
 
 Glossary 71 
 
 Plague, or bubonic plague. Essentially a disease of rodents (rats, 
 squirrels, and related animals). Transmitted from rat to rat and 
 from rat to men by fleas. The disease has long prevailed in the 
 Orient, particularly in India. It has appeared in the United. States 
 only a few times. About 1903 or 1904 it was introduced into Cali- 
 fornia, and since then has appeared twice in New Orleans and other 
 Gulf ports. A vigorous campaign of rat-killing has eradicated the 
 disease each time it has appeared in this country, although it is 
 said still to exist among California ground squirrels. 
 
 An outstanding feature of plague is its method of traveling from 
 country to country. It seems to be carried exclusively by the Nor- 
 way rat, which, by the way, is a 'great traveler, by boat and by 
 rail. If plague-infected rats go aboard a boat and other rats on 
 the ship get infected, the disease may develop at sea. Then at any 
 port where the boat touches, the rats may disembark and introduce 
 the disease. 
 
 Pneumonia. Aside from tuberculosis, this disease causes more 
 deaths than any other in this country. The death rate from pneu- 
 monia is generally higher in the colder latitudes than in the warmer. 
 The fever runs high, and the breathing is very rapid. In about 5 
 to 8 days from the onset there occurs what is called the "crisis." 
 The patient breaks out in a profuse sweat, the temperature falls 
 rapidly to normal or below, and the patient goes into a state of 
 collapse. It is at this juncture that most deaths occur. If the patient 
 can get through the crisis all right, he will probably recover. One 
 student, when asked what pneumonia was, replied: "A kind of cold 
 in the lungs." The description is good. 
 
 Poliomyelitis (pol-e-o-mi-e-li'tis). From the Greek words polios, 
 "gray," and muelos, "marrow"; combined with Uis, meaning an 
 inflammation; literally, "inflammation of gray matter." Commonly 
 called infantile paralysis. This disease is very insidious. The child 
 complains of not feeling well perhaps does not eat any breakfast, 
 and is disinclined to play. In a day or two it is noticed that he is 
 partly paralyzed in one or more limbs. As the paralysis is caused 
 by the destruction of the nerves in the spinal cord that lead to the 
 muscles, there is little that can be done for it. 
 
 Rabies, or hydrophobia. Transmitted through the bite of an 
 animal infected with rabies. Once developed, the disease is always 
 fatal. It is usually about 4 weeks sometimes more, sometimes 
 less from the time the person is bitten until he develops the 
 disease. If during this time he takes the Pasteur treatment (the 
 only effective method of vaccinating against rabies), he will not be 
 likely to develop rabies. But it takes 3 to 4 weeks to give the Pasteur 
 treatment; so there is no time to be lost. If you are bitten by an
 
 72 Glossary 
 
 animal and are not sure whether it is rabid or not, the thing to do 
 is to begin the Pasteur treatment at once do not wail. Then, shut 
 up the animal to keep him from biting any one else, or other animals, 
 and watch him for further symptoms of rabies. If he has the disease, 
 he will die in 3 or 4 days. If he does not die in a week, you will 
 know that it is not rabies, and you can drop the treatment. Above 
 all things do not kill the dog. You can be much more certain by 
 watching him than by sending his head to the laboratory. If you 
 do kill the dog, you will have to complete the Pasteur treatment 
 regardless of what the laboratory finds. If you do not kill the dog, 
 you may be able to drop the treatment in a week or so. 
 Rocky Mountain spotted fever. (See pages 28 and 39.) 
 
 Scarlet fever. (Scarlatina is only another name for the same 
 disease.) One of the eruptive fevers. Characterized by sore throat 
 and a scarlet rash. In later stages of the disease the epidermis 
 (outer skin) sheds off more or less. In some cases the hands peel 
 off almost like taking off a glove. In mild cases there is not much 
 of this shedding, or "desquamation" as it is called in books. 
 
 Scarlet fever sometimes injures the hearing. There is a little tube 
 running from the throat to the ear that enables air to get to the 
 middle ear. It is called the Eustachian tube. When it becomes 
 inflamed, as it often does in scarlet fever, it may "grow together," 
 so that air cannot pass through it. Inflammation of the middle 
 ear is a common complication; in that case hearing may be per- 
 manently damaged. 
 
 Septicemia. In typhoid, child-bed fever, and some other condi- 
 tions, the germs causing the disturbance exist and multiply in the 
 blood stream. Such conditions are spoken of as "septicemia." 
 
 Smallpox. A disease that has always been looked on with great 
 dread. Formerly a most terrible scourge, but now comparatively 
 unimportant. Sometimes today a case is fatal, but not often. Can 
 be prevented by vaccination. It is customary to make some attempt 
 to quarantine it, but as a general rule that does little, if any, good. 
 Only about one out of every four cases is ever reported to the health 
 officer. It is perfectly obvious that to quarantine one case and 
 leave three at large will do very little good in checking its spread. 
 Every one who wants to keep from having smallpox should be 
 vaccinated against it and keep on getting vaccinated until it "takes." 
 If it does not "take," it does not show that you are immune against 
 the disease it more probably shows that the vaccine was dead. 
 And it is not true that people sometimes have to have the arm 
 taken off because of vaccination that never happens. (See page 53.) 
 
 Tetanus, or lockjaw. A disease that is caused by the germ of 
 tetanus. The germ gets into a wound, particularly the deep or
 
 Glossary 73 
 
 "puncture" wounds, and the poison that comes from their growth 
 acts on the nervous system, causing the muscles to contract; hence 
 the jaws seem locked. The tetanus germ is particularly prevalent 
 about stables. Puncture wounds received about barns should be 
 promptly attended to. 
 
 Lockjaw can be prevented by the use of tetanus antitoxin, which 
 is in the market. All persons who get suspicious wounds will be 
 safe if they take an injection of this germ, which is called "anti- 
 tetanic serum." Gunpowder wounds are particularly dangerous 
 sources of tetanus. (See page 58.) 
 
 Trachoma. A disease of the eyelids. Often called "granulated 
 lids," but there are many cases of "granulated lids" that are not 
 trachoma. True trachoma is such a serious disease that persons 
 who have it are not permitted to come to this country as immigrants. 
 At Ellis Island, where most of the immigrants land, all are examined 
 and those found to have trachoma are sent back. There are some 
 cases in this country, however. It is fairly amenable to treatment 
 by operative procedure. 
 
 Trichinosis (trich-i-no'is). Most commonly a disease of hogs and 
 rats. Very rare among human beings in the United States. A tiny 
 worm, the trichinella spiralis, causes the disease. There are thou- 
 sands of them coiled up in the muscles of a single infected animal. 
 It is this that causes "measly pork." When a person eats such 
 pork without sufficient cooking to kill the worms, he gets the disease 
 himself. In man it is somewhat like rheumatism in its effects. 
 At the packing houses all pork is examined for these little worms, 
 and whenever found, the carcass is condemned. 
 
 This is another disease in which the rat is often involved. Rats 
 eat scraps of meat and get the infection. Pigs may eat rats, and 
 man eats the pigs. The disease is more interesting than important. 
 
 Tuberculosis. (See page 61.) 
 
 Typhoid fever. A long-drawn-out fever lasting usually from 3 to 6 
 weeks. Caused by a vegetable germ, the typhoid bacillus. These 
 germs are passed from the body of the patient by millions, in the 
 saliva, in the urine, and in the stools. Consequently all sewage is 
 to be regarded as typhoid infected. And if through any means it 
 contaminates the drinking-water, persons drinking this water will 
 have typhoid fever. This may happen when a surface privy is close 
 to a well. The sewage from the privy seeps down when it rains, 
 and gets into the well. Or it may happen from emptying sewage 
 into a river and taking water from the river for domestic use. All 
 such water should be filtered by the city. Typhoid is often spread 
 when flies have access to open privies. They go there to feed, get 
 the germs on their feet, and then come into the dining room and 
 walk over the food.
 
 74 Glossary 
 
 Sometimes a person may get well from typhoid and still give off 
 the germs for weeks or months, or even years. Such persons are 
 called "typhoid carriers." If a typhoid carrier works in a dairy 
 or as a cook, or otherwise handles food, there is danger of spreading 
 the disease. It is customary now to examine all milkers in large 
 dairies to make sure that they are not typhoid carriers. Many 
 epidemics of typhoid have been caused by carriers. 
 
 It is possible now to be effectively vaccinated against typhoid. 
 (See page 49.) 
 
 Typhus. Also known as "jail fever." Transmitted by both head 
 and body lice. Caused many deaths during the recent war. Not 
 common in the United States. Caused only 16 deaths here during 
 the year 1917. Every precaution is taken at Ellis Island and other 
 immigration stations to prevent its accidental introduction. 
 
 Venereal diseases. There are three venereal diseases: syphilis, 
 gonorrfiea, chancroid. All are contracted by sexual contact. These 
 diseases are the most terrible of all diseases, causing a great deal 
 of suffering insanity, blindness, disabilities, and deaths both 
 directly and indirectly. 
 
 It should be clearly understood that no one who lives a clean sexual 
 life is in danger from these diseases. 
 
 On page 30 there is a table listing the most salient features of 
 the venereal diseases; if you wish to know more about them, ask 
 your family physician he will be glad to tell you all about them. 
 
 Whooping-cough. A widely known disease, and much more serious 
 than generally considered. In 1917, for example, in the list of 
 communicable diseases it stood eighth as a cause of deaths. It caused 
 more deaths that year than scarlet fever, malaria, smallpox, hook- 
 worms, and hydrophobia combined. It is particularly fatal among 
 infants and very young children. It should never be considered 
 lightly. And above all, children should not be exposed io it (o "get 
 
 Yellow fever. A disease that is now of more historic than practical 
 interest. It used to prevail in Cuba constantly, and every year or 
 so it was introduced into the United States. All sorts of theories 
 were proposed as to how it spread. But. in 1900 a commission headed 
 by Walter Reed of the United States Army, working in Cuba, 
 proved that it was transmitted by mosquitoes, of the genus then 
 known as Culex Jascialus, but which is now known as .-Edcx calopus. 
 
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