Part 60

History of the Outbreak. The outbreak commenced early in January, without any obvious occasion for the introduction of infection. There had been no chicken disease on the place for 25 years, and no chickens had been purchased except from a neighboring farm where the stock remained healthy. They had been fed on corn meal, wheat bran, wheat tailings and whole corn, together with scorched wheat from a burned barn. The poultry houses were clean and well aired, and after they had been closed there was no abatement of the disease. The water was from a stagnant pool receiving drainage from the stable, but this was no new condition and January is not the driest month with the foulest water. The suggestion may be hazarded that the infection may have been introduced by the usual infection bearer, the buzzard, or by some other wild bird, or mammal.

Pathogenesis. Among the chickens the most rapid and fatal cases were in pullets, then among the laying hens, while the capons and cockerels were less severely affected, and some survived from three to seven days.

Those inoculated intravenously as a rule sickened on the second or third day with a temperature of 110.7° F., and were found dead the following morning.

Some took injections of .25 to 1cc. in the pectoral muscles with impunity.

Chickens that had fasted 24 hours, took each daily for 3 days, a few cubes of bread soaked in a fresh bouillon culture. Death followed in four out of six, in from four to thirteen days from the beginning of the experiment. The birds gradually became listless, refused to eat, and remained quiet in a corner of the cage, with closed eyes and head drooping until it rested on the ground. Diarrhœa was frequent but not invariably present.

Chickens fed on the chopped up viscera of rabbits that had died of the disease perished in 3 to 10 days.

A white duck inoculated intravenously with .5cc. of peptonized beef bouillon culture, took ill on the 8th day, and died on the 12th. There was loss of coördination and use of the wings, temperature 109° F., and necropsy showed valvular endocarditis containing the streptococcus. A second duck sickened on the 11th day, but recovered after three days’ illness. Killed on 21st day, all cultures from heart, spleen and kidney remained sterile. Subcutaneous, intramuscular and feeding experiments failed to produce the disease in ducks.

A pigeon injected with .5cc. bouillon culture intravenously died on the fourth day with the internal lesions of chickens, and blood extravasations on head and neck. Intra-muscular injections and feeding experiments were fruitless.

In rabbits, intravenous injections of 1 to 1.5cc. led in 24 hours, to temperature of 105.3° F., without impairment of appetite, or other marked sign of illness, and as a rule the subject is found dead next morning. Intra-abdominal and intrapleural injections kill in two to four days, and subcutaneous ones in three days. In addition to the lesions found in chickens, there is often bloody urine, a sanguineous lymph on and beneath the cerebral meninges and in the fourth ventricle, and deep congestion of the cancellated tissue of the vertebræ. Streptococci are abundant in the lesions.

In mice intraabdominal injection of .01cc. killed in 48 hours, and subcutaneous injections in 2 to 5 days. The lesions were like those seen in birds, and streptococci were abundant.

In dogs after intravenous injection there was hyperthermia (103.6° and 104.1° F.) and lameness of the right fore shoulder joint, followed in 5 to 8 days by recovery. Feeding on the viscera of the diseased chickens, was followed by anorexia, and vomiting only.

Guinea pigs and sheep proved refractory.

Immunization. The injection into the wing vein of .5 to 2.5cc. of bouillon culture, sterilized by heat proved protective to the chickens against inoculations of the virus while the check animals invariably died.

TUBERCULOSIS.

Synonyms. Definition: infectious disease caused by bacillus, attended by productive inflammation, tubercles, necrotic degeneration, caseation, fibroid change, calcification or ulceration. Animals susceptible: python, salamander, carp, fish, birds, rodents, sheep, goats, solipeds, cattle, dogs, cats, apes, swine, wild ruminants, kangaroo, carnivora, cage birds, civilized (housed) man. Geographical distribution: with dense population, Central Europe, Britain, Eastern States; little in absence of cattle products—Scottish Western Isles, Iceland, Newfoundland, Greenland Highlands, Arctic North America, Northern Norway, Sweden, Lapland: open air life protects. Virulence: ancient records, modern, early antituberculous legislation, decimation of herds, researches of Vilemin, Gerlach, Chauveau, Semmer, Parrot, Tappeiner, etc. Bacillus tuberculosis: evolutionary changes, relation to actinomyces, 1.5 to 3.5μ by 0.2μ shorter and thicker in ox, solitary, exceptionally short chains, on blood serum may be filamentous, staining slow, carbolated fuchsin, technique, sections; biology, adaptation to environment, to genera, variation in same genus, experiments showing real identity of variant forms; vitality: in water human bacillus 50 to 70 days, bovine bacillus indefinitely, avian 117 days, dried sputa 9 months, cow’s lung 102 days, putrid material 43 days to years, survives gastric juice, sunlight kills in some hours, if in thin layer, day light 7 to 18 days, dry heat (212° F.) for an hour left living bacilli, moist heat 140° F. for 1 hour kills, low temperatures (−25° F.) fail, after 15 days in salt failed in rabbit, after 30 in Guinea pig. Chemical disinfectants. Accessory causes: racial vulnerability, close buildings, dark, foul, damp stables, poor scanty food, heavy milking, conformation, early breeding, inbreeding, age, predisposing diseases, traffic in animals, dairy extension, admission of tuberculous animals from other states, assorting tuberculous for sale in a given State, sale of sound from tuberculous herd, lack of indemnity for animals killed, private testing of herds and sale of tuberculous, accustoming to tuberculin test, antipyretics during tuberculin test, false certificates of tuberculin tests, feeding hogs on tuberculous offal, feeding calves and hogs on tuberculous milk, feeding hogs after tuberculous cattle, feeding from a common trough, dry, dusty stables, extension through vermin, flies and other insects carry virus. The tubercle: miliary, pinhead, conglomerate, proliferation of cells—tissue and leucocytes, in nests in stroma, giant cells in center, then epithelioid, then lymphoid, caseation, calcification, fibrosis, pearl disease. Localization: Cattle: pulmonary: miliary tuberculosis, aggregation into larger tubercles, caseated centres, fibroid, cretified, abscesses, vomicæ, complex infections, infiltrations, difference from broncho-pneumonia, lesions of different ages; pleural lesions; congestion, exudation, fringes, nodules, grapes, adhesions, caseations: bronchial and mediastinal glands, congestion, swelling, softening, induration, caseation, cretefaction: cardiac lesions: lesions of mouth and throat, pharyngeal glands: gastro-intestinal, peritoneal, mesenteric glandular; œsophagastoma; liver tubercle; splenic; pancreatic; genito-urinary; mammary; cerebral; spinal; orbital; skeletal; cutaneous; muscular; glandular; table of distribution. Swine: lesions: pharyngeal, intestinal, mesenteric, muscular, hepatic, splenic, glandular, pulmonary, skeletal, caseation, liquefaction. Horse: lesions: thoracic, abdominal, glandular, of serosæ, vertebræ, etc. Sheep and goat: lesions: thoracic, abdominal, glandular, hepatic, pharyngeal, facial, etc., verminous affections. Dog and Cat: lesions: respiratory, abdominal, pharyngeal, tonsillar, hepatic, pancreatic, splenic, skeletal, arthritic, cutaneous. Apes and Menagerie Animals: lesions. Chickens: lesions: intestines, liver, spleen, peritoneum: lungs and kidneys often escape. Pheasant: lesions: as in hens, centre zone has epithelioid cells, fibroid, cretefaction, amyloid degeneration. Parrot: lesions: eye, beak, tongue, palate, larynx, bones, joints, lungs, liver, intestines, muscles, skin. Primary and secondary infection, extension by lymphatics, blood channels, tonsils, inhalation, deglutition.

Synonyms. Consumption; Tabes; Scrofula; Pining; Grapes; Great White Plague, etc.

Definition. An infectious disease common to man and a large number of animals, caused by the bacillus tuberculosis, and characterized by a productive inflammation giving rise to small, rounded bodies (tubercles), or diffuse infiltration, with a tendency to necrotic degeneration, and caseation, or to fibroid degeneration (sclerosis), calcification or ulceration.

Animals susceptible. Tuberculosis comes near to being a panzoötic, since although reptiles, fishes, birds and some mammals do not readily contract it under normal conditions, yet under abnormal and debilitating conditions nearly all will succumb to it.

Reptiles. Sutton found tuberculosis in a python which was kept so warm in the London Zoological Gardens that a thermometer between its folds registered 85° F. Kráhl, Battaillon and Ferre cultivated the bacillus in frogs, Kráhl in snakes. Blauvelt found tuberculosis in a salamander. Lechner found it in amphibia.

Fishes. Broussais records the prevalence of tuberculosis in carp in a pond which received the sputa of a consumptive man. Under the skin were found rounded tumors, containing abundance of bacilli, that infected rabbits and Guinea pigs on which they were inoculated.

Birds. In birds of the farmyard—hens, pheasants, turkeys, ducks and pigeons—it is very frequent and often occurs as an epizoötic. While the tuberculosis of barnyard fowl is a manifest variety and not readily interchangeable with the varieties affecting the mammal, yet, with a special predisposition, it can be transferred and can then be conveyed from animal to animal in the new genus in which it has been implanted. That of cage birds is interchangeable with that of man.

Rodents. Guinea pigs have a strong susceptibility to tuberculosis, whether from human or bovine source, and rabbits for that of birds, and by continuous transmission through the body of the rodent, all alike seem to tend toward acquiring common characters. The Guinea-pig, therefore, has been especially availed of for the experimental transmission of tuberculosis, and, as the disease in them becomes acute and rapid in its progress, these subjects permit the multiplying of experiments in a short period. Rabbits are less vulnerable to the bovine or human form.

Sheep and goats, kept under usual conditions, show a remarkable immunity from tuberculosis, yet if directly inoculated an inherent susceptibility is easily shown. Habitual immunity may be in some degree due to their open air life, to the heavy winter fleece protecting them against chills, to the comparative absence of the heavy and continuous milk yield demanded of cows, to the more restricted development of the lymph plexuses in the lungs and elsewhere, and to the limited opportunity offered by the small tonsils for infection entrance.

The horse, ass and mule rarely contract tuberculosis casually, the more spacious stall, outdoor life, hard muscular condition, the very small tonsils, the exclusive nasal respiration, the paucity of connective tissue lymph plexuses, and the abundance of red globules, probably favor immunity. Yet on inoculation by Chauveau, Nocard and others, the horse readily succumbed to infection, generalization taking place more certainly than in the ox.

Cattle. The bovine races are remarkably subject to tuberculosis. This is probably due in part to the great amount of connective tissue lymph plexus in the lungs and elsewhere, the habit of using the mouth in hurried breathing, the deep, sudden inspiration through the mouth and over the tonsils that follows a cough, the habitual restricted size of the cow stables, the absence of individual separated stalls, the habit of feeding from the same trough with the cattle adjacent, the great drain of yearly breeding and heavy milking, the retention in the herd of old, failing cows for their milk product and high priced offspring, and the bovine habit of licking each other with the infected tongue. In many European cities and even in country districts the disease is very prevalent. In Copenhagen a few years ago 17.7 per cent. of all oxen and cows killed in the abattoirs were tuberculous; in Berlin 15 per cent.; in Holland 20 per cent.; in Pomerania and Bomberg 50 per cent.; in Hildesheim, Hanover, 50 per cent.; in Berlin dairies 75 per cent. (Ostertag): in Leipsic and Edinburgh 20 per cent. The great variation in the data for the different cities is suggestive of different inspection standards. American figures as given by the Bureau of Animal Industry are for Baltimore (mostly cows recently from the country) 2.5 to 3.5 per cent.; and for the packing centers (among 2,273,547 mostly fat steers, and therefore selected) 0.02 per cent. It is here largely a matter of locality and infection, I have seen large herds with 100 per cent. tuberculous, and extensive districts, in the north and especially in the south entirely free from the disease.

Dogs and cats in their natural condition rarely show the disease, but contract it readily on inoculation. Cadiot found 40 cases in 9,000 post mortems of dogs. The young are apparently more susceptible than the old, and primary lesions in the abdomen are common and suggest infection through the food. The majority belonged to consumptive persons, and gnawed the bones that had been first picked by the owner, and ate from his plate what he left. Jacobi records the case of a dog, with general tuberculosis, which habitually licked up the expectorations of his phthisical master.

Apes and Monkeys, in confinement, almost all die of tuberculosis.

Swine contract tuberculosis readily, the large tonsils, the habit of breathing through the mouth, and the abundance of connective tissue and lymph plexuses in the lungs and elsewhere contributing to this. Yet in them the affection is mainly a dietetic disease. Swine kept in the country and fed on vegetable food are rarely affected. In Saxony, where 17 per cent. of the cattle are tuberculous only a shade over one per cent. of swine were so, and in Baden only 0.02 per cent. In hogs raised on our western farms and corn-fed the proportion is much less. Yet in those fed on uncooked skim milk, kitchen scraps and the refuse of slaughterhouses in a raw state, tuberculosis becomes very common. In one case, in a large public institution, where the dairy herd was universally affected, and where, on their slaughter, their raw offal had been thrown to the hogs, I found that the latter were almost all tuberculous. Similarly, in feeding experiments, from the time of Gerlach, pigs and especially young pigs, have shown themselves to be very susceptible.