- Email: [email protected]
Management—A Factor in Combating Avian Tuberculosis
MANAGEMENT—A
FACTOR IN COMBATING TUBERCULOSIS
AVIAN
L. D. BUSHNBLL and W. R. HINSHAW INTRODUCTION
REVIEW OF LITEEATURE
An extensive review of the literature ΛνΐΠ not be made here. The reader is referred to the excellent summaries by Hastings and Halpin (1), Van Es and Schalk (2), Calmette (3), Moore (4), and others. The disease was first reported in America by Pernot (5) in 1900, although it had undoubtedly been observed long before that time. Moore and Ward (6) described an outbreak of the disease in 1903 and Edwards (7) refers to a few articles pub lished on this disease in 1911. Hastings and Halpin (1) report that the disease was found in poultry in Wisconsin in 1906. It was reported from New York in 1906 (8), from southern Michi gan in 1907 (9)· from Nevada in 1908 (10), and from Minnesota in 1909 (11). In Kansas we have personal knowledge of its be ing present since 1908, since a diagnosis was made in the bac teriological laboratories at that time. During the past few years there has been a marked increase in the number of cases of this disease reported. This is prob ably partly due to the increased poultry population, to the rapid shipments of poultry to various parts of the country from dis' Contribution No. 76, Department of Bacteriology. Presented in part before the Short Course in Poultry Husbandry at the Kansas State Ag ricultural College, Feb. 5, 1925. 35
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
The disease avian tuberculosis is of great importance not only as a disease of domestic fowls, but also because it may be trans mitted from fowls to other types of live stock. Until the past year it was considered of importance mainly to the poultry in dustry, but since the work of Dr. L. Van Bs of Nebraska the disease has assumed a far greater importance than formerly. We may now think of the disease not entirely as a menace to poultry, but also to other animals and possibly to man himself. With this point in mind the management of a flock of tubercu lous poultry acquires new aspects and is of greater importance.
36
POULTRY
SCIENCE
tant sources, and to the fact that people are beginning to rec ognize the disease and to realize its importance from an econ omic and public health standpoint. DISTBIBUTIOISr OF T H E DISEASE
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
The literature on avian tuberculosis shows that the disease is widely scattered and is probably common in every civilized country in the world. All types of birds, whether tame or in captivity, are susceptible to the disease. The most commonly affected are the barnyard ΐοΛν^, pigeons, turkeys, pheasants, guinea fowls, swans, canaries and parrots. It has been found in from 25 to 30 percent of birds in zoological gardens. According to Calmette (3) the disease is not found among wild birds any where in the world except those in captivity or living near the habitation of man. Sparrows, pigeons and other birds which migrate from flock to flock may become infected and transmit the disease. Fox (12) states that "Birds have a high receptivity and sus ceptibility to tuberculosis. The type of disease is essentially the same throughout the class. Certain varieties of the Galle and Columbae, for instance, have a very high incidence of di sease, whereas the Herondiones seem to have no receptivity for the organisms. Other water birds like the Odontoglossae and the Fulicariae have also no receptivity." This author was un able to explain this difference in receptivity. Werkman and Gibbs (13) made a survey of tuberculosis of poultry in Idaho by application of the tuberculin test. From one series of tests on 856 birds from 127 flocks in all parts of the state they found tuberculosis in 18.3 per cent. Frequently they found as high as 80 per cent of the individual fowls in fected. Dimock and Willey (14) state that at the Iowa Experiment Station from 1915 to 1918 there were examined 227 fowls. Of these 36.57 per cent were found to be affected with tuberculosis. During the past four years an effort has been made at Kansas Agricultural Experiment Station to tabulate the distribution of this disease in Kansas. Our records are made only on ma terial shipped to the laboratory from various places in the state. This survey will give only a general idea of the distribu-
MAifAGEMENT—COMBATING
AVIAN
TUBERCULOSIS
37
Map Showing Distribution of Avian Tuberculosis in K a n s a s (Determined by Actual Diagnosis of Cases) ECONOMIC IMPORTANCE
There is no evidence upon which to base a reliable estimate of the actual losses inflicted by this disease. The problem has been further complicated by the fact that farm animals and perhaps man may acquire the infection from diseased birds. Another factor to be considered in this connection is that birds suffering from the disease do not die as rapidly as in more acute infections, but linger for several weeks or months with continual loss of weight and egg production and still maintain a normal food consumption. Most of these birds are not in marketable condition at the end of this period and if put on the market at all must sell as culls. In the future, poultry dealers will be less and less inclined to buy such birds since they represent a much greater loss to them than they do the farmer and poultry raiser. Reports have been made in which the infection ran as high as 50 to 75 per cent of the birds in a flock. Probably the usual
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
tion of the disease in the state, but no idea at all as to its prevalence. During this time the disease has been definitely diagnosed on 91 farms in 40 counties. The reason it was not found in all the other counties is because no birds have been received which happened to liave the disease. There is no reason to doubt that it is in every county in the state.
POULTRY
38
SCIENCE
number is about 50 per cent of the adult fowls and a considerably smaller number of the younger birds. The influence of age is illustrated from a table published by Van Es and Schalk (2) PERCENTAGE OF INFECTION
1 2 3 4
3.33 24.35 86.44 85.71
Werkman and Gibbs (13) obtained the following results at the Idaho Experiment Station by the use of the tuberculin test. AGE OF BIRDS
PERCENTAGE OF REACTORS
Pullets and Cockerels Two years Three years Older t h a n t h r e e y e a r s
0.19 21.10 28.95 52.04
These tables are significant in that they show that older birds are much more highly infected and, as a result, more dangerous in the spread of the infection. They also emphasize the chronic nature of the disease. In an acute infectious disease the fowls either die rapidly or recover completely in a relatively short time. ETIOLOGY
At the present time bacteriologists consider four distinct types of the tubercle bacillus—the human, the bovine, the avian and the piscine. The human type is found chietly affecting man; the bovine chiefly, cattle and hogs ; the avian type chiefly, birds ; and the piscine type, cold blooded animals of various kinds. These bacilli are fairly distinct types of the same organism, and at one time it was supposed that there was no cross infection by the various types. Later investigation, however, showed clearly that human beings could be infected by the bovine type, especially during childhood. It is now known that the hog is easily infected by the human, bovine, and avian organism. In fact, one feeding of material containing any of these organisms may be sufficient to cause the disease in hogs. It is not possible
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
AGE OF BIRD I N YEARS
MANAGEMENT—COMBATING
AYIAN
TUBERCULOSIS
39
to distinguish with certainty which type of infection is present without a bacteriological examination. TRANSMUTATION OF TYPES OF TUBERCLE BACILLI
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
There has been a great deal of experimental work done in attempting to transform one type of the tubercle bacillus into another type. Koch did not consider that there was transmutation of types and finally concluded that there was little or no cross infection by tlie various types of this organism. At present there is little doubt of cross infection in many cases although the different classes of animals affected show quite different pathological changes. Fischel (15) considered from his study of bovine and human tubercle bacilli that the culture medium influenced the infectiousness of various strains of tubercle bacilli. He could not agree with Koch and Mafucci that there was a sharp, difference between the different types of these organisms. He considered that the various types may be transferred from one to another through intermediate forms, and that the various types depend upon the nutrient which they have received. Bang (16) succeeded in changing the mammalian tubercle bacilli to types which behaved like the avian bacilli. Nocard (17) placed human tubercle bacilli in collodion sacs in the peritoneal cavity of hens. After five to eight months the birds were killed. The organisms from these sacs were very similar to the avian type of bacilli. After a third passage in the sacs the author succeeded in causing typical disease in hens by intravenous and intraperitoneal inoculation of these cultures. This author thinks that all tubercle bacilli are simply variations of one type of organism. Cornet and Kossel (18) could not change the nature of the avian type by introducing it into the body of guinea pigs. Schroeder, (19) states that an impartial study of the available evidence lea\'es little doubt that the tubercle bacilli may be divided into at least three distinct types : the human, the bovine, and the avian, and no one acquainted with the enormous number of unsuccessful attempts that have been made to transform one type into another will be led far astray by superficially plausable transformation theories, or find encouragement in such
40
POULTRY
SCIENCE
THE RELATION OF AVIAN TUBERCULOSIS TO TUBERCULOSIS OF MAMMALS
The relation of avian tuberculosis to tuberculosis in hogs was studied by the English Royal Commission in 1911. They found the avian bacillus in five instances among 26 cases of glandular tuberculosis in hogs, but the disease was of non-progressive type. Mohler and "Washburn (20) were able to infect hogs by feeding tissues of tuberculous birds. According to the investigations of Calmette (3) the horse is quite susceptible to the avian type of bacilli. In this animal the intravenous injection produced a generalized disease which progressed rapidly. Cattle are much less susceptible, but repeated ingestion will produce mesenteric gland infection with extensive caseous areas in the Peyer's patches. Hastings and Halpin (1) produced tuberculosis in hogs by feeding tubercular tissue from birds. The disease was localized in their animals and not generalized as that commonly found on feeding bovine tubercle bacilli. "Weber and Bofinger (21) fed a cat with organs of a tuber-
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
theories for the belief that the distinctive characters of the different types lack permanence or stability. He states also that guinea pigs are highly susceptible to human and bovine types and strongly resistant against the avian type. Rabbits are strongly resistant against the human type which readily attacks guinea pigs and are quite susceptible to the avian type, against which the guinea pig is so strongly resistant. If the difference were purely a question of degree and not of kind of pathogenicity, either guinea pigs would not be more vulnerable to the human type than rabbits, or rabbits would not be more vulnerable to the avian type than the guinea pigIn discussing the epidemic and epizootic significance of the different types of tubercle bacilli this writer concludes that the epizootic prevalence of tuberculosis among fowls is dependent upon the avian type of the tubercle bacillus, which lacks the power to serve as the cause of an epidemic or an epizootic occurrence of tuberculosis among mammals. The human and the bovine types of the tubercle bacillus have no significance as a cause for the epizootic development of tuberculosis among fowls.
MANAGEMENT—COMBATING
ΑΎΙΑΝ
TUBERCULOSIS
41
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
eulous hen and produced no infection. De Jong (22) (23) fed cultures of avian tuberculosis repeat edly to a year old heifer, a 14 day calf, a goat and a pig. Four months later they were killed. The heifer showed only small lesions in the mesentery and lungs. The calf showed about the same lesions but with a somewhat more generalized condition in the glands of the pharynx. The goat showed but a slight lesion while the pig showed numerous tubercular abscesses in the phar ynx and swollen tubercular retropharyngeal glands. Mettam (24) fed a two year old bull with a culture of avian tuberculosis. The animal was slaughtered three and one-half months later and showed numerous small tubercles in the mesentery. Titze (25) fed four pigs with 40 glycerine serum cultures of the avian tubercle bacillus. One died in the course of five months with generalized tuberculosis. Two others were slaughtered and showed tubercular abscesses while one did not show the disease. He also fed a colt with 44 cultures with no result. Bang (16) fed two horses, one colt, three calves, two young goats and seven kids with avian tubercle bacilli. He found that, while young animals were susceptible, old animals were very resistant. In his article he includes reports on numerous feed ing experiments of this kind. In one instance he fed calves with avian bacilli which resulted in the involvement of the mesenteric and intestinal lymph glands and death in from iive to eight weeks. Carl (26) examined a series of avian tuberculosis cultures which showed very dry growth similar to that of the human type. These were cultured for two years. Inoculation with fresh and cultured material gave stronger virulence with the fresh. Inoculation of fresh material subcutaneously into two rabbits caused death in eight days of miliary tuberculosis of all organs. Of two guinea pigs one died of local tuberculosis, the second in 158 days of generalized tuberculosis. A second inoculation caused death in 136 days. A third generation caused disease only in regional lymph nodes. One hen fed fresh ma terial did not die. Intraperitoneal inoculation of four hens caused generalized tuberculosis. The virulence for birds had not changed on artificial media.
POULTRY
42
SCIENCE
Christiansen (27) examined tuberculosis material from 118 hogs and found the distribution of lesions as follows— LOCAL
LOCAL jLANDS OF
PHABYNGEAI. GLANDS
N E C K AND PHARYNGEAL GLANDS
NECK
G L A N D S AND ORGANS
ο •^
ο ί»
61
< 58
a ·Μ ο
•a
S M y 1 2
A
•rt
α) >.
a
û, -t?
j - ·
H
7
a>i
^ φ
r
15
^
s
i» fq
^M
7
1
Ο ^
^ 9
-5 >
-< 9
a
ï a
Κ 4-? .« ο
ίΰ 0) •-
M S . . ._
a
!>> a;
Sο
a 53
c •"
^
> ^
S .a m s
33
12
20
•aφ
1
The organisms were isolated from 86 of the 118 cases. These agreed with the avian type bacillus in every case. Bovine tu berculosis was found in 28 hogs. In four cases the organisms were different. From two of these they were closely related to the avian type, one resembled the human type and one was more closely related to the bovine tJφe. When the avian type was found in organs the disease was strongly localized and showed little involvement of the entire organ. When the involvement was widespread in an organ the bovine type was present. Bang (16) observed tuberculosis in pigs in a yard in which avian tuberculosis was present. The infection was largely lo calized in the glands of the neck and intestines of these animals and showed no tendency to become generalized. Four hens and two rabbits were inoculated with this material and all died of tuberculosis. Three guinea pigs were inoculated, but with the exception of a small lesion in the lymph gland of the flank none showed tuberculosis after three months. The organism was isolated from the hens and was of typical avian type. Bang mentions a case of acute tuberculous pneumonia in a pig due to avian type tubercle bacillus. From two yards in which there were tuberculous birds, 33 per cent and 66 per cent of the hogs were tuberculous. Two pigs infected with avian type tuberculo sis were injected with avian and human tuberculin. Both gave the reaction, but it was greater with tuberculin prepared from the avian type. Nocard (28) recognized tuberculosis in the horse in two forms:—That of the lung and that of the abdominal region. From the abdominal type he isolated a strain of tubercle bac illi which was similar, but not identical with the avian type.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
φ
<"
MANAGEMENT—COMBATING
AVIAN
TUBERVULOSIS
43
The examination of cultures of the avian tubercle bacilli by guinea pig injection has been used by numerous authorities. Maffuchi and others could not succeed in infecting these animals while Feber and Bofinger, by injection of eleven different strains, produced only localized disease at point of inoculation and in the regional lymph glands. They did not find that inhalation of these organisms caused this disease. Steriopoulo (29) produced tuberculosis in two goats by means of avian tubercle bacilli obtained from intestinal nodules in a fowl. Injections were made intravenously. Before inoculation the animals did not react to tuberculin. The first animal died in 17 days after the injection. The second appeared in good health but had lost ten pounds in two weeks. This animal died in seven days after injection of tuberculin. Post mortem ex-
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
The cultural features agreed with that of the avian type and inoculation into rabbits and hens indicated that it was very similar. The pathological changes due to those organisms were not of the ordinary kind. This author considers that there are transition forms between the mammalian and the avian strains. Nocard (17) also considers from his work on types isolated from the horse, that the lung form of the disease was due to the mammalian type of the organism and the abdominal form to the avian type. He found that the human type Avas not highly infectious for guinea pigs, but was for rabbits. From the spleen of these infected rabbits he isolated cultures very similar to those of the avian type. When inoculated into birds they were virulent but showed lesions similar to those of the avian type. Cornet and Kossel (18) made a report on avian tuberculosis as it affects birds and laboratory animals. The duration of the disease in birds after intraperitoneeal injection is two to four months; after subcutaneous, six months; after feeding, 12 months. The various modes of introduction of the organism result in different types of the disease. There may be a tuberculosis septicemia (the so-called Yersin type) in which there is a swelling of the organs without formation of tubercles; or an acute miliary tuberculosis (the Villemin type) ; or finally the chronic type of the disease with localization and tubercle formation. The type of disease depends on the dosage, portal of entry, and virulence of the organism.
44
POULTRY
SCIENCE
Kossel, Weber, and Heuss (31) studied five strains of avian tubercle bacilli and found by subcutaneous inoculation into calves that there resulted local pus formation and gland involvement. The feeding of 32 glycerine cultures of this organism to a calf in the course of six weeks caused miliary tuberculosis, involvement of the Peyer's patches and the mesenteric and retropharyngeal glands. Himmelberger (32) made a careful study of the infectiousness of the avian type tuberculosis to animals. He was unable to infect white rats under conditions closely simulating cohabitation with diseased birds. His attempts to infect a limited number of guinea pigs and rabbits resulted negatively except in one rabbit. This worker found that calves could be infected with the avian bacillus. After feeding with tuberculous material all developed a severe diarrhea four or five days after ingestion. This condition lasted nearly five weeks in one calf. The chief lesions produced in calves by this material were in
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
amination showed desquamation pneumonia. The liver showed fatty degeneration with necrotic areas, and the kidneys showed glomerulo-nephritis. Pure cultures were obtained from the blood of the second animal. Romer (30) studied cultures isolated from hens. These cultures killed white mice in about four weeks with generalized tuberculosis, and caused death of guinea pigs when injected in large doses. Death appeared to be due to intense intoxication with swelling of the spleen, fibrinous peritonitis, hyperemia of the lungs and exudate in the thoracic and peritoneal cavities. The rabbit was more susceptible to this type than the guinea pig. The ox was also very susceptible to these cultures. Injected with 0.002 gm. of dried fresh culture there was pneumonia with generalization of the disease and rapid loss of weight. These cultures had been obtained from birds which had contracted the disease after feeding tuberculous material from cattle. When these cultures were injected into other birds they did not succumb to the disease. He found also that animals inoculated with these cultures reacted with tuberculin made with the avian organism. He seemed to think that tubercle bacilli virulent for one animal would be virulent for all under like conditions.
MANAGEMENT—COMBATING
AVIAN
TUBERCULOSIS
45
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
the mesenteric and intestinal lymph nodes and ulcers in the in testinal mucosa. Day (33) studied tuberculosis of the skin and body lymph nodes in swine. He received tuberculous material from an abattoir and inoculated guinea pigs, rabbits and two hogs with the culture. The rabbits and guinea pigs were killed two months later with negative findings. The hogs died of another disease. Later a puppy and kitten were inoculated subeutaneously, and a sheep and pig intravenously with negative results, with the exception of a small abscess at the point of inoculation in the puppy and kitten. These abscesses subsided after two or three weeks. A second lot of material was injected into a hog which later showed localized lesions of the disease. Two young roosters were inoculated from the lesions found in the hog. These birds were later slaughtered and a few lesions of the disease were found. He states that the extent of the lesions in the skin in swine depend largely upon the length of the time during which the animal has been infected. Van Es, (34) in a statistical study of the retentions and condemnations of swine in abattoirs, showed that the number of retentions in these animals had increased from approximately 14 per thousand slaughtered in 1907, to 164 per thousand slaughtered in 1922, while the condemnation of animals showed no such increase. He also found that the proportion of reten tions and condemnations of cattle was nearly the same for that period. In discussing this he emphasizes the following points:— The type of tuberculosis of swine which leads to condemna tion has not materially increased during those years, Λvhile the type of localized, non-progressive tuberculosis, not resulting in condemnation, has in the same time increased more than twelve times in frequency. A study of the data presented makes it apparent that there is a discrepancy between the incidence of bovine and swine retentions on account of tuberculosis which, to say the least, somewhat denies the prevailing theory that most if not all tuber culosis in swine is traceable to tuberculous cattle. Two conspicuous facts stand out as a possible explanation of
46
POULTRY
SCIENCE
INFECTION T Y P E
Mammalian Avian Mixed Total No. shipments
NO.
11 185 13 209
PERCENT
5.21 88.51 6.22 99.94
"The results of the Nebraska inquiry clearly indicate that contact with avian infection is responsible for a predominating portion of the cases of swine tuberculosis subject to retention at packing establishments and that there is warrant to believe that the great increase in the incidence of this type of swine tuberculosis is but a consequence of the great prevalence and spread of tuberculosis among farm poultry in the areas involved. ' ' A survey was made of 16 farms from which infected , swine were received. This showed that on 14 the poulti;y M^as the only source of infection ; one showed the disease in both cattle and fowls ; and one farm on which only the mammalian type was found in swine the cattle were diseased but the poultry were absolutely free from tuberculosis. Fourteen consignments of tubercular material from Hillsdale County, Michigan, an area free from bovine tuberculosis, showed 13 to be of the avian type and one of mixed avian and bovine type.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
the phenomenon described and are offered as a hypothesis to be proved or disproved by actual investigation. It has been known for 20 years that swine are susceptible to the tuberculosis naturally occurring in poultry. It is equally known that tuberculosis among farmyard poultry, has since 1907, enormously increased its prevalence in a very large section of the country. The material used by Van Es in his investigation consisted of tuberculous lymph nodes obtained from swine affected with the type of localized tuberculosis responsible for the increased number of retentions. The material was received from Federal meat inspectors at Omaha, Sioux City, Nebraska City and St. Joseph. Classification of the type of infection was based on the results of inoculation into guinea pigs and fowls. The final results are shown in the following table.
MANAGEMENT—COMBATING
AVIAN
TUBERCULOSIS
47
THE EBDATION OF AVIAN TUBERCULOSIS TO THE DISEASE IN MAN
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
The exact significance of avian tuberculosis to man cannot be determined. The meat of the domestic foAvl is rarely eaten without thorough cooking and the fact that the organism can rarely be found in eggs, even from tuberculous hens as shown by the work of Fitch, Lubbenhusen and Dikmans (35), leads to doubt about its significance in these products. These inves tigators examined eggs from a flock of 62 tuberculous hens, but found that only 43 produced eggs at all. A total of 876 eggs were examined and the germ of tuberculosis found only once in a composite of nine eggs from two hens. They conclude from these results that less than 1 per cent of eggs from tuberculous fowls actually contain tubercle bacilli. Werkman and Gibbs (13) made a field test in egg produc tion comparing tuberculous and non-tuberculoiis foΛvls. The average daily egg production of 67 healthy fowls was 26.7, while that of the tuberculous group was 8.2. Thus, the, egg seems to be of minor importance in the spread of this disease. Mohler and Washburn (20), however, found the organism to be present in eggs from tuberculous hens and considered that eggs from such birds should be considered dangerous until cooked. There are some instances on record in which the avian type of tubercle bacillus has been isolated from human beings suffer ing from tuberculosis. Lowenstein( 36) found it in kidney tu berculosis of two children, and in a cutaneous form Avith abscesses and ulcerations in the nose and intestines. He believed that the infection must have resulted from the eating of infected eggs, either raw or poorly cooked, and considers this type of the di sease to be more common in man than is usually accepted. Jansco and Elfer (37) found them in pure state in the mesenteric glands of a girl 8 years of age. Lipschutz (38) asserts that avian bacilli are frequently found in certain forms of cutaneous tu berculosis in man, as Elder and Lee (39) have recently found to be the ease in cattle. Cornet and Kossel (18) compiled a table of 1290 eases of tuberculosis in man. Among these they report the avian type of tubercle bacillus in three cases. One a ease of disease of the
48
POULTRY
SCIENCE
MODE OF TRANSMISSION TO OTHER BIRDS
When we bear in mind the fact that tuberculosis is an infec tious disease and can only come from a previous case of the same disease it is easy to see that it will not become established in a healthy flock without the introduction from without of some bird already affected, or by moving the healthy birds to already infected pens. The disease in chickens is localized chiefly in the intestines, or organs · receiving a blood supply directly from the intestinal region. Many of the nodules on the Λvalls of the intestine have openings into the lumen and material may continually pass from the lesion and be voided in the droppings. Such material gets into the feed and water, it is then consumed by other birds and the infection is spread in this manner. Birds allowed to eat the carcasses of birds dead of the disease, or the offal of diseased birds which are dressed for the table may eas ily become infected. In some cases birds do not show visible signs of the disease, or the disease may be passed unrecognized. For this reason, birds should never be fed offal or carcasses from other birds, even though they appear to be entirely healthy. The tubercle bacillus probably does not grow in nature outside the animal body but can remain alive for some time if protected from the direct rays of the sun. It is not killed by freezing or by drying for a short time, but is killed in a few minutes by direct sunlight. Numerous experiments have been made to determine how birds may be naturally infected. Authorities differ as to the rate at
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
lungs, one a ease of generalized tuberculosis and one tubercu losis of the abdominal organs. Koch and Eobinowitsch (40) cultured a similar tubercle bac illus from the spleen of a man dead of miliary tuberculosis. Although the avian type of organism does not appear to be especially dangerous in food products it may be spread by duist. Large numbers of tubercle bacilli pass out of the intestines of the tuberculous bird with the droppings. The area or house oc cupied by birds is always very dusty, so that the organisms would be continually thrown into the air and might be trans mitted in this manner. While the avian type of infection is rare in human beings it does occur occasionally.
MANAGEMENT—COMBATING
AVIAN TUBERCULOSIS
49
Fic. II. Diagramatic representation of open an closed tuberculous lesions on the intestinal wall of a bird.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
which the organisms may pass from a diseased bird in the droppings. This will differ with different birds and with the same bird at different times. I t is agreed, however, that the exit with the feces is practically the only i m p o r t a n t method of elimination, since the disease is rarely severe in the lungs of birds and material is rarelv coughed out.
50
POULTRY
SCIENCE
In Figure II, A indicates graphically ΙΙΟΛΥ the tubercle bacilli may pass into the lumen of the intestine from an open lesion. Such conditions do not always exist even in cases of tubercu losis. In Β is shown a lesion on the wall of the intestine, but which had no connection with the lumen. Such a lesion \vould not give off the organisms. An open lesion may become closed or a closed lesion break doAvn and become open. Thus the elim ination of the organisms Avill be intermittent. There are numerous points to consider in interpreting the conditions found on post mortem. In the first place a bird may have a very severe ease of the disease but show no lesions open ing into the intestinal tract. Such a bird would not be danger ous in association with other birds. Another bird, very slightly affected, may have the lesions so localized that they constantly excrete enormous numbers of bacilli. There is also marked variability in the virulence of organisms from different cases.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
Vu:. III. Actual photograph of open tuberculosis ulcers on the intestinal wall.
MANAGEMENT—COMBATING
AVIAN
TUBERCULOSIS
51
Sustmann, (42), studied an outbreak of tuberculosis in a breeding pen of several young turkeys aged from four to twelve weeks. Two older birds had died in this pen about three months previously. The young birds were sick three to eight days while the old birds died suddenly. Sustmann examined the two older birds, one about half groAvn and ten smaller ones. In all thirteen he found tuberculosis in lungs and intestines and in the older birds in the liver. In the young chicks not only the lungs, but also the peritoneum was covered with knot-like areas. The contents of these lesions showed many tubercle bacilli. Spread of the Infection Through the Egg :—Considerable work has been done to show the relation between infection of the egg and spread of the disease within a flock. Tubercle bacilli have been found in the white of the egg by several investigators, but most of them consider that the infected embryos die in a short
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
Thus, the dosage and the virulence will determine to a large extent the spread of the disease within a flock. The former may be controlled very largely by proper sanitation. Infection by Feeding:—Weber and Boflnger (21) always succeeded in producing the disease by feeding of pure cultures of the organism and cadavers of animals dead of avian type of the disease. Edwards (7) fed five healthy hens and two cocks on droppings of tuberculous fowls. In all eleven feedings were given over a period of 20 days. Of the seven birds thus fed, four died of the disease within six months and the remainder died later of other causes. Giltner (9) kept seven hens in contact with tuberculous birds in an uncleaned pen but failed to obtain infection. Later tests in Avhich he kept healthy hens in close contact with badly diseased birds failed to show the disease after five months. Hastings, Halpin and Beach (41) obtained nine hens from a diseased flock. These were placed with seven healthy birds in a small uncleaned room for a month. After 10, 26, and 46 days three of the diseased birds succumbed, the remaining six were killed one year later and all but one showed the disease. One of the originally healthy hens was killed after eight months and showed tuberculous lesions. The others were killed after one year and an examination showed that two of the six Avere tuberculous.
52
POULTRY
SCIENCE
(To Be Concluded in t h e Next Issue)
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
time. Maffuchi (43), however, showed that infected embryos would continue to develop. Artault (44) made a study of the bacteria in eggs and by rabbit inoculation found the tubercle bacillus to be present in two of 25 eggs. Gartner (45) injected pure culture of this organism into 12 female and one male canary birds. From these birds he got nine eggs. The egg material was injected intraperitoneally into guinea pigs and two were found to contain the tubercle organisms. In a second experiment he injected 25 canary birds. Prom these he obtained 24 eggs, two of which were found to eontain the organism. Koch and Eobinowitsch (40) injected tubercle bacilli into 32 eggs. Fourteen were infected with avian type, eleven with human type and seven with bovine type. Bight chicks were hatched from these eggs. Of these one had been infected with the avian type, three with human type and four with bovine type. The chick infected with avian type died in 75 days with generalized tuberculosis. The chicks from the eggs infected with human type were killed after 133 days but no trace of disease could be found. Of the four chicks hatched from the eggs infected with the bovine type, one died in 33 days with tuberculosis of the caecum, one died at 137 days with tuberculosis of intestines and liver and two were killed but showed no disease. Baumgarten (46) injected several eggs with a culture of avian type but only two hatched. One of the chicks died in four months with generalized tuberculosis. The second died in four and one-half months of tapeworm infestation, but showed a few lesions of the disease in the peritoneum, liver and spleen.
FACTOR IN COMBATING TUBERCULOSIS
AVIAN
L. D. BUSHNBLL and W. R. HINSHAW INTRODUCTION
REVIEW OF LITEEATURE
An extensive review of the literature ΛνΐΠ not be made here. The reader is referred to the excellent summaries by Hastings and Halpin (1), Van Es and Schalk (2), Calmette (3), Moore (4), and others. The disease was first reported in America by Pernot (5) in 1900, although it had undoubtedly been observed long before that time. Moore and Ward (6) described an outbreak of the disease in 1903 and Edwards (7) refers to a few articles pub lished on this disease in 1911. Hastings and Halpin (1) report that the disease was found in poultry in Wisconsin in 1906. It was reported from New York in 1906 (8), from southern Michi gan in 1907 (9)· from Nevada in 1908 (10), and from Minnesota in 1909 (11). In Kansas we have personal knowledge of its be ing present since 1908, since a diagnosis was made in the bac teriological laboratories at that time. During the past few years there has been a marked increase in the number of cases of this disease reported. This is prob ably partly due to the increased poultry population, to the rapid shipments of poultry to various parts of the country from dis' Contribution No. 76, Department of Bacteriology. Presented in part before the Short Course in Poultry Husbandry at the Kansas State Ag ricultural College, Feb. 5, 1925. 35
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
The disease avian tuberculosis is of great importance not only as a disease of domestic fowls, but also because it may be trans mitted from fowls to other types of live stock. Until the past year it was considered of importance mainly to the poultry in dustry, but since the work of Dr. L. Van Bs of Nebraska the disease has assumed a far greater importance than formerly. We may now think of the disease not entirely as a menace to poultry, but also to other animals and possibly to man himself. With this point in mind the management of a flock of tubercu lous poultry acquires new aspects and is of greater importance.
36
POULTRY
SCIENCE
tant sources, and to the fact that people are beginning to rec ognize the disease and to realize its importance from an econ omic and public health standpoint. DISTBIBUTIOISr OF T H E DISEASE
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
The literature on avian tuberculosis shows that the disease is widely scattered and is probably common in every civilized country in the world. All types of birds, whether tame or in captivity, are susceptible to the disease. The most commonly affected are the barnyard ΐοΛν^, pigeons, turkeys, pheasants, guinea fowls, swans, canaries and parrots. It has been found in from 25 to 30 percent of birds in zoological gardens. According to Calmette (3) the disease is not found among wild birds any where in the world except those in captivity or living near the habitation of man. Sparrows, pigeons and other birds which migrate from flock to flock may become infected and transmit the disease. Fox (12) states that "Birds have a high receptivity and sus ceptibility to tuberculosis. The type of disease is essentially the same throughout the class. Certain varieties of the Galle and Columbae, for instance, have a very high incidence of di sease, whereas the Herondiones seem to have no receptivity for the organisms. Other water birds like the Odontoglossae and the Fulicariae have also no receptivity." This author was un able to explain this difference in receptivity. Werkman and Gibbs (13) made a survey of tuberculosis of poultry in Idaho by application of the tuberculin test. From one series of tests on 856 birds from 127 flocks in all parts of the state they found tuberculosis in 18.3 per cent. Frequently they found as high as 80 per cent of the individual fowls in fected. Dimock and Willey (14) state that at the Iowa Experiment Station from 1915 to 1918 there were examined 227 fowls. Of these 36.57 per cent were found to be affected with tuberculosis. During the past four years an effort has been made at Kansas Agricultural Experiment Station to tabulate the distribution of this disease in Kansas. Our records are made only on ma terial shipped to the laboratory from various places in the state. This survey will give only a general idea of the distribu-
MAifAGEMENT—COMBATING
AVIAN
TUBERCULOSIS
37
Map Showing Distribution of Avian Tuberculosis in K a n s a s (Determined by Actual Diagnosis of Cases) ECONOMIC IMPORTANCE
There is no evidence upon which to base a reliable estimate of the actual losses inflicted by this disease. The problem has been further complicated by the fact that farm animals and perhaps man may acquire the infection from diseased birds. Another factor to be considered in this connection is that birds suffering from the disease do not die as rapidly as in more acute infections, but linger for several weeks or months with continual loss of weight and egg production and still maintain a normal food consumption. Most of these birds are not in marketable condition at the end of this period and if put on the market at all must sell as culls. In the future, poultry dealers will be less and less inclined to buy such birds since they represent a much greater loss to them than they do the farmer and poultry raiser. Reports have been made in which the infection ran as high as 50 to 75 per cent of the birds in a flock. Probably the usual
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
tion of the disease in the state, but no idea at all as to its prevalence. During this time the disease has been definitely diagnosed on 91 farms in 40 counties. The reason it was not found in all the other counties is because no birds have been received which happened to liave the disease. There is no reason to doubt that it is in every county in the state.
POULTRY
38
SCIENCE
number is about 50 per cent of the adult fowls and a considerably smaller number of the younger birds. The influence of age is illustrated from a table published by Van Es and Schalk (2) PERCENTAGE OF INFECTION
1 2 3 4
3.33 24.35 86.44 85.71
Werkman and Gibbs (13) obtained the following results at the Idaho Experiment Station by the use of the tuberculin test. AGE OF BIRDS
PERCENTAGE OF REACTORS
Pullets and Cockerels Two years Three years Older t h a n t h r e e y e a r s
0.19 21.10 28.95 52.04
These tables are significant in that they show that older birds are much more highly infected and, as a result, more dangerous in the spread of the infection. They also emphasize the chronic nature of the disease. In an acute infectious disease the fowls either die rapidly or recover completely in a relatively short time. ETIOLOGY
At the present time bacteriologists consider four distinct types of the tubercle bacillus—the human, the bovine, the avian and the piscine. The human type is found chietly affecting man; the bovine chiefly, cattle and hogs ; the avian type chiefly, birds ; and the piscine type, cold blooded animals of various kinds. These bacilli are fairly distinct types of the same organism, and at one time it was supposed that there was no cross infection by the various types. Later investigation, however, showed clearly that human beings could be infected by the bovine type, especially during childhood. It is now known that the hog is easily infected by the human, bovine, and avian organism. In fact, one feeding of material containing any of these organisms may be sufficient to cause the disease in hogs. It is not possible
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
AGE OF BIRD I N YEARS
MANAGEMENT—COMBATING
AYIAN
TUBERCULOSIS
39
to distinguish with certainty which type of infection is present without a bacteriological examination. TRANSMUTATION OF TYPES OF TUBERCLE BACILLI
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
There has been a great deal of experimental work done in attempting to transform one type of the tubercle bacillus into another type. Koch did not consider that there was transmutation of types and finally concluded that there was little or no cross infection by tlie various types of this organism. At present there is little doubt of cross infection in many cases although the different classes of animals affected show quite different pathological changes. Fischel (15) considered from his study of bovine and human tubercle bacilli that the culture medium influenced the infectiousness of various strains of tubercle bacilli. He could not agree with Koch and Mafucci that there was a sharp, difference between the different types of these organisms. He considered that the various types may be transferred from one to another through intermediate forms, and that the various types depend upon the nutrient which they have received. Bang (16) succeeded in changing the mammalian tubercle bacilli to types which behaved like the avian bacilli. Nocard (17) placed human tubercle bacilli in collodion sacs in the peritoneal cavity of hens. After five to eight months the birds were killed. The organisms from these sacs were very similar to the avian type of bacilli. After a third passage in the sacs the author succeeded in causing typical disease in hens by intravenous and intraperitoneal inoculation of these cultures. This author thinks that all tubercle bacilli are simply variations of one type of organism. Cornet and Kossel (18) could not change the nature of the avian type by introducing it into the body of guinea pigs. Schroeder, (19) states that an impartial study of the available evidence lea\'es little doubt that the tubercle bacilli may be divided into at least three distinct types : the human, the bovine, and the avian, and no one acquainted with the enormous number of unsuccessful attempts that have been made to transform one type into another will be led far astray by superficially plausable transformation theories, or find encouragement in such
40
POULTRY
SCIENCE
THE RELATION OF AVIAN TUBERCULOSIS TO TUBERCULOSIS OF MAMMALS
The relation of avian tuberculosis to tuberculosis in hogs was studied by the English Royal Commission in 1911. They found the avian bacillus in five instances among 26 cases of glandular tuberculosis in hogs, but the disease was of non-progressive type. Mohler and "Washburn (20) were able to infect hogs by feeding tissues of tuberculous birds. According to the investigations of Calmette (3) the horse is quite susceptible to the avian type of bacilli. In this animal the intravenous injection produced a generalized disease which progressed rapidly. Cattle are much less susceptible, but repeated ingestion will produce mesenteric gland infection with extensive caseous areas in the Peyer's patches. Hastings and Halpin (1) produced tuberculosis in hogs by feeding tubercular tissue from birds. The disease was localized in their animals and not generalized as that commonly found on feeding bovine tubercle bacilli. "Weber and Bofinger (21) fed a cat with organs of a tuber-
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
theories for the belief that the distinctive characters of the different types lack permanence or stability. He states also that guinea pigs are highly susceptible to human and bovine types and strongly resistant against the avian type. Rabbits are strongly resistant against the human type which readily attacks guinea pigs and are quite susceptible to the avian type, against which the guinea pig is so strongly resistant. If the difference were purely a question of degree and not of kind of pathogenicity, either guinea pigs would not be more vulnerable to the human type than rabbits, or rabbits would not be more vulnerable to the avian type than the guinea pigIn discussing the epidemic and epizootic significance of the different types of tubercle bacilli this writer concludes that the epizootic prevalence of tuberculosis among fowls is dependent upon the avian type of the tubercle bacillus, which lacks the power to serve as the cause of an epidemic or an epizootic occurrence of tuberculosis among mammals. The human and the bovine types of the tubercle bacillus have no significance as a cause for the epizootic development of tuberculosis among fowls.
MANAGEMENT—COMBATING
ΑΎΙΑΝ
TUBERCULOSIS
41
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
eulous hen and produced no infection. De Jong (22) (23) fed cultures of avian tuberculosis repeat edly to a year old heifer, a 14 day calf, a goat and a pig. Four months later they were killed. The heifer showed only small lesions in the mesentery and lungs. The calf showed about the same lesions but with a somewhat more generalized condition in the glands of the pharynx. The goat showed but a slight lesion while the pig showed numerous tubercular abscesses in the phar ynx and swollen tubercular retropharyngeal glands. Mettam (24) fed a two year old bull with a culture of avian tuberculosis. The animal was slaughtered three and one-half months later and showed numerous small tubercles in the mesentery. Titze (25) fed four pigs with 40 glycerine serum cultures of the avian tubercle bacillus. One died in the course of five months with generalized tuberculosis. Two others were slaughtered and showed tubercular abscesses while one did not show the disease. He also fed a colt with 44 cultures with no result. Bang (16) fed two horses, one colt, three calves, two young goats and seven kids with avian tubercle bacilli. He found that, while young animals were susceptible, old animals were very resistant. In his article he includes reports on numerous feed ing experiments of this kind. In one instance he fed calves with avian bacilli which resulted in the involvement of the mesenteric and intestinal lymph glands and death in from iive to eight weeks. Carl (26) examined a series of avian tuberculosis cultures which showed very dry growth similar to that of the human type. These were cultured for two years. Inoculation with fresh and cultured material gave stronger virulence with the fresh. Inoculation of fresh material subcutaneously into two rabbits caused death in eight days of miliary tuberculosis of all organs. Of two guinea pigs one died of local tuberculosis, the second in 158 days of generalized tuberculosis. A second inoculation caused death in 136 days. A third generation caused disease only in regional lymph nodes. One hen fed fresh ma terial did not die. Intraperitoneal inoculation of four hens caused generalized tuberculosis. The virulence for birds had not changed on artificial media.
POULTRY
42
SCIENCE
Christiansen (27) examined tuberculosis material from 118 hogs and found the distribution of lesions as follows— LOCAL
LOCAL jLANDS OF
PHABYNGEAI. GLANDS
N E C K AND PHARYNGEAL GLANDS
NECK
G L A N D S AND ORGANS
ο •^
ο ί»
61
< 58
a ·Μ ο
•a
S M y 1 2
A
•rt
α) >.
a
û, -t?
j - ·
H
7
a>i
^ φ
r
15
^
s
i» fq
^M
7
1
Ο ^
^ 9
-5 >
-< 9
a
ï a
Κ 4-? .« ο
ίΰ 0) •-
M S . . ._
a
!>> a;
Sο
a 53
c •"
^
> ^
S .a m s
33
12
20
•aφ
1
The organisms were isolated from 86 of the 118 cases. These agreed with the avian type bacillus in every case. Bovine tu berculosis was found in 28 hogs. In four cases the organisms were different. From two of these they were closely related to the avian type, one resembled the human type and one was more closely related to the bovine tJφe. When the avian type was found in organs the disease was strongly localized and showed little involvement of the entire organ. When the involvement was widespread in an organ the bovine type was present. Bang (16) observed tuberculosis in pigs in a yard in which avian tuberculosis was present. The infection was largely lo calized in the glands of the neck and intestines of these animals and showed no tendency to become generalized. Four hens and two rabbits were inoculated with this material and all died of tuberculosis. Three guinea pigs were inoculated, but with the exception of a small lesion in the lymph gland of the flank none showed tuberculosis after three months. The organism was isolated from the hens and was of typical avian type. Bang mentions a case of acute tuberculous pneumonia in a pig due to avian type tubercle bacillus. From two yards in which there were tuberculous birds, 33 per cent and 66 per cent of the hogs were tuberculous. Two pigs infected with avian type tuberculo sis were injected with avian and human tuberculin. Both gave the reaction, but it was greater with tuberculin prepared from the avian type. Nocard (28) recognized tuberculosis in the horse in two forms:—That of the lung and that of the abdominal region. From the abdominal type he isolated a strain of tubercle bac illi which was similar, but not identical with the avian type.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
φ
<"
MANAGEMENT—COMBATING
AVIAN
TUBERVULOSIS
43
The examination of cultures of the avian tubercle bacilli by guinea pig injection has been used by numerous authorities. Maffuchi and others could not succeed in infecting these animals while Feber and Bofinger, by injection of eleven different strains, produced only localized disease at point of inoculation and in the regional lymph glands. They did not find that inhalation of these organisms caused this disease. Steriopoulo (29) produced tuberculosis in two goats by means of avian tubercle bacilli obtained from intestinal nodules in a fowl. Injections were made intravenously. Before inoculation the animals did not react to tuberculin. The first animal died in 17 days after the injection. The second appeared in good health but had lost ten pounds in two weeks. This animal died in seven days after injection of tuberculin. Post mortem ex-
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
The cultural features agreed with that of the avian type and inoculation into rabbits and hens indicated that it was very similar. The pathological changes due to those organisms were not of the ordinary kind. This author considers that there are transition forms between the mammalian and the avian strains. Nocard (17) also considers from his work on types isolated from the horse, that the lung form of the disease was due to the mammalian type of the organism and the abdominal form to the avian type. He found that the human type Avas not highly infectious for guinea pigs, but was for rabbits. From the spleen of these infected rabbits he isolated cultures very similar to those of the avian type. When inoculated into birds they were virulent but showed lesions similar to those of the avian type. Cornet and Kossel (18) made a report on avian tuberculosis as it affects birds and laboratory animals. The duration of the disease in birds after intraperitoneeal injection is two to four months; after subcutaneous, six months; after feeding, 12 months. The various modes of introduction of the organism result in different types of the disease. There may be a tuberculosis septicemia (the so-called Yersin type) in which there is a swelling of the organs without formation of tubercles; or an acute miliary tuberculosis (the Villemin type) ; or finally the chronic type of the disease with localization and tubercle formation. The type of disease depends on the dosage, portal of entry, and virulence of the organism.
44
POULTRY
SCIENCE
Kossel, Weber, and Heuss (31) studied five strains of avian tubercle bacilli and found by subcutaneous inoculation into calves that there resulted local pus formation and gland involvement. The feeding of 32 glycerine cultures of this organism to a calf in the course of six weeks caused miliary tuberculosis, involvement of the Peyer's patches and the mesenteric and retropharyngeal glands. Himmelberger (32) made a careful study of the infectiousness of the avian type tuberculosis to animals. He was unable to infect white rats under conditions closely simulating cohabitation with diseased birds. His attempts to infect a limited number of guinea pigs and rabbits resulted negatively except in one rabbit. This worker found that calves could be infected with the avian bacillus. After feeding with tuberculous material all developed a severe diarrhea four or five days after ingestion. This condition lasted nearly five weeks in one calf. The chief lesions produced in calves by this material were in
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
amination showed desquamation pneumonia. The liver showed fatty degeneration with necrotic areas, and the kidneys showed glomerulo-nephritis. Pure cultures were obtained from the blood of the second animal. Romer (30) studied cultures isolated from hens. These cultures killed white mice in about four weeks with generalized tuberculosis, and caused death of guinea pigs when injected in large doses. Death appeared to be due to intense intoxication with swelling of the spleen, fibrinous peritonitis, hyperemia of the lungs and exudate in the thoracic and peritoneal cavities. The rabbit was more susceptible to this type than the guinea pig. The ox was also very susceptible to these cultures. Injected with 0.002 gm. of dried fresh culture there was pneumonia with generalization of the disease and rapid loss of weight. These cultures had been obtained from birds which had contracted the disease after feeding tuberculous material from cattle. When these cultures were injected into other birds they did not succumb to the disease. He found also that animals inoculated with these cultures reacted with tuberculin made with the avian organism. He seemed to think that tubercle bacilli virulent for one animal would be virulent for all under like conditions.
MANAGEMENT—COMBATING
AVIAN
TUBERCULOSIS
45
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
the mesenteric and intestinal lymph nodes and ulcers in the in testinal mucosa. Day (33) studied tuberculosis of the skin and body lymph nodes in swine. He received tuberculous material from an abattoir and inoculated guinea pigs, rabbits and two hogs with the culture. The rabbits and guinea pigs were killed two months later with negative findings. The hogs died of another disease. Later a puppy and kitten were inoculated subeutaneously, and a sheep and pig intravenously with negative results, with the exception of a small abscess at the point of inoculation in the puppy and kitten. These abscesses subsided after two or three weeks. A second lot of material was injected into a hog which later showed localized lesions of the disease. Two young roosters were inoculated from the lesions found in the hog. These birds were later slaughtered and a few lesions of the disease were found. He states that the extent of the lesions in the skin in swine depend largely upon the length of the time during which the animal has been infected. Van Es, (34) in a statistical study of the retentions and condemnations of swine in abattoirs, showed that the number of retentions in these animals had increased from approximately 14 per thousand slaughtered in 1907, to 164 per thousand slaughtered in 1922, while the condemnation of animals showed no such increase. He also found that the proportion of reten tions and condemnations of cattle was nearly the same for that period. In discussing this he emphasizes the following points:— The type of tuberculosis of swine which leads to condemna tion has not materially increased during those years, Λvhile the type of localized, non-progressive tuberculosis, not resulting in condemnation, has in the same time increased more than twelve times in frequency. A study of the data presented makes it apparent that there is a discrepancy between the incidence of bovine and swine retentions on account of tuberculosis which, to say the least, somewhat denies the prevailing theory that most if not all tuber culosis in swine is traceable to tuberculous cattle. Two conspicuous facts stand out as a possible explanation of
46
POULTRY
SCIENCE
INFECTION T Y P E
Mammalian Avian Mixed Total No. shipments
NO.
11 185 13 209
PERCENT
5.21 88.51 6.22 99.94
"The results of the Nebraska inquiry clearly indicate that contact with avian infection is responsible for a predominating portion of the cases of swine tuberculosis subject to retention at packing establishments and that there is warrant to believe that the great increase in the incidence of this type of swine tuberculosis is but a consequence of the great prevalence and spread of tuberculosis among farm poultry in the areas involved. ' ' A survey was made of 16 farms from which infected , swine were received. This showed that on 14 the poulti;y M^as the only source of infection ; one showed the disease in both cattle and fowls ; and one farm on which only the mammalian type was found in swine the cattle were diseased but the poultry were absolutely free from tuberculosis. Fourteen consignments of tubercular material from Hillsdale County, Michigan, an area free from bovine tuberculosis, showed 13 to be of the avian type and one of mixed avian and bovine type.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
the phenomenon described and are offered as a hypothesis to be proved or disproved by actual investigation. It has been known for 20 years that swine are susceptible to the tuberculosis naturally occurring in poultry. It is equally known that tuberculosis among farmyard poultry, has since 1907, enormously increased its prevalence in a very large section of the country. The material used by Van Es in his investigation consisted of tuberculous lymph nodes obtained from swine affected with the type of localized tuberculosis responsible for the increased number of retentions. The material was received from Federal meat inspectors at Omaha, Sioux City, Nebraska City and St. Joseph. Classification of the type of infection was based on the results of inoculation into guinea pigs and fowls. The final results are shown in the following table.
MANAGEMENT—COMBATING
AVIAN
TUBERCULOSIS
47
THE EBDATION OF AVIAN TUBERCULOSIS TO THE DISEASE IN MAN
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
The exact significance of avian tuberculosis to man cannot be determined. The meat of the domestic foAvl is rarely eaten without thorough cooking and the fact that the organism can rarely be found in eggs, even from tuberculous hens as shown by the work of Fitch, Lubbenhusen and Dikmans (35), leads to doubt about its significance in these products. These inves tigators examined eggs from a flock of 62 tuberculous hens, but found that only 43 produced eggs at all. A total of 876 eggs were examined and the germ of tuberculosis found only once in a composite of nine eggs from two hens. They conclude from these results that less than 1 per cent of eggs from tuberculous fowls actually contain tubercle bacilli. Werkman and Gibbs (13) made a field test in egg produc tion comparing tuberculous and non-tuberculoiis foΛvls. The average daily egg production of 67 healthy fowls was 26.7, while that of the tuberculous group was 8.2. Thus, the, egg seems to be of minor importance in the spread of this disease. Mohler and Washburn (20), however, found the organism to be present in eggs from tuberculous hens and considered that eggs from such birds should be considered dangerous until cooked. There are some instances on record in which the avian type of tubercle bacillus has been isolated from human beings suffer ing from tuberculosis. Lowenstein( 36) found it in kidney tu berculosis of two children, and in a cutaneous form Avith abscesses and ulcerations in the nose and intestines. He believed that the infection must have resulted from the eating of infected eggs, either raw or poorly cooked, and considers this type of the di sease to be more common in man than is usually accepted. Jansco and Elfer (37) found them in pure state in the mesenteric glands of a girl 8 years of age. Lipschutz (38) asserts that avian bacilli are frequently found in certain forms of cutaneous tu berculosis in man, as Elder and Lee (39) have recently found to be the ease in cattle. Cornet and Kossel (18) compiled a table of 1290 eases of tuberculosis in man. Among these they report the avian type of tubercle bacillus in three cases. One a ease of disease of the
48
POULTRY
SCIENCE
MODE OF TRANSMISSION TO OTHER BIRDS
When we bear in mind the fact that tuberculosis is an infec tious disease and can only come from a previous case of the same disease it is easy to see that it will not become established in a healthy flock without the introduction from without of some bird already affected, or by moving the healthy birds to already infected pens. The disease in chickens is localized chiefly in the intestines, or organs · receiving a blood supply directly from the intestinal region. Many of the nodules on the Λvalls of the intestine have openings into the lumen and material may continually pass from the lesion and be voided in the droppings. Such material gets into the feed and water, it is then consumed by other birds and the infection is spread in this manner. Birds allowed to eat the carcasses of birds dead of the disease, or the offal of diseased birds which are dressed for the table may eas ily become infected. In some cases birds do not show visible signs of the disease, or the disease may be passed unrecognized. For this reason, birds should never be fed offal or carcasses from other birds, even though they appear to be entirely healthy. The tubercle bacillus probably does not grow in nature outside the animal body but can remain alive for some time if protected from the direct rays of the sun. It is not killed by freezing or by drying for a short time, but is killed in a few minutes by direct sunlight. Numerous experiments have been made to determine how birds may be naturally infected. Authorities differ as to the rate at
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
lungs, one a ease of generalized tuberculosis and one tubercu losis of the abdominal organs. Koch and Eobinowitsch (40) cultured a similar tubercle bac illus from the spleen of a man dead of miliary tuberculosis. Although the avian type of organism does not appear to be especially dangerous in food products it may be spread by duist. Large numbers of tubercle bacilli pass out of the intestines of the tuberculous bird with the droppings. The area or house oc cupied by birds is always very dusty, so that the organisms would be continually thrown into the air and might be trans mitted in this manner. While the avian type of infection is rare in human beings it does occur occasionally.
MANAGEMENT—COMBATING
AVIAN TUBERCULOSIS
49
Fic. II. Diagramatic representation of open an closed tuberculous lesions on the intestinal wall of a bird.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
which the organisms may pass from a diseased bird in the droppings. This will differ with different birds and with the same bird at different times. I t is agreed, however, that the exit with the feces is practically the only i m p o r t a n t method of elimination, since the disease is rarely severe in the lungs of birds and material is rarelv coughed out.
50
POULTRY
SCIENCE
In Figure II, A indicates graphically ΙΙΟΛΥ the tubercle bacilli may pass into the lumen of the intestine from an open lesion. Such conditions do not always exist even in cases of tubercu losis. In Β is shown a lesion on the wall of the intestine, but which had no connection with the lumen. Such a lesion \vould not give off the organisms. An open lesion may become closed or a closed lesion break doAvn and become open. Thus the elim ination of the organisms Avill be intermittent. There are numerous points to consider in interpreting the conditions found on post mortem. In the first place a bird may have a very severe ease of the disease but show no lesions open ing into the intestinal tract. Such a bird would not be danger ous in association with other birds. Another bird, very slightly affected, may have the lesions so localized that they constantly excrete enormous numbers of bacilli. There is also marked variability in the virulence of organisms from different cases.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
Vu:. III. Actual photograph of open tuberculosis ulcers on the intestinal wall.
MANAGEMENT—COMBATING
AVIAN
TUBERCULOSIS
51
Sustmann, (42), studied an outbreak of tuberculosis in a breeding pen of several young turkeys aged from four to twelve weeks. Two older birds had died in this pen about three months previously. The young birds were sick three to eight days while the old birds died suddenly. Sustmann examined the two older birds, one about half groAvn and ten smaller ones. In all thirteen he found tuberculosis in lungs and intestines and in the older birds in the liver. In the young chicks not only the lungs, but also the peritoneum was covered with knot-like areas. The contents of these lesions showed many tubercle bacilli. Spread of the Infection Through the Egg :—Considerable work has been done to show the relation between infection of the egg and spread of the disease within a flock. Tubercle bacilli have been found in the white of the egg by several investigators, but most of them consider that the infected embryos die in a short
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
Thus, the dosage and the virulence will determine to a large extent the spread of the disease within a flock. The former may be controlled very largely by proper sanitation. Infection by Feeding:—Weber and Boflnger (21) always succeeded in producing the disease by feeding of pure cultures of the organism and cadavers of animals dead of avian type of the disease. Edwards (7) fed five healthy hens and two cocks on droppings of tuberculous fowls. In all eleven feedings were given over a period of 20 days. Of the seven birds thus fed, four died of the disease within six months and the remainder died later of other causes. Giltner (9) kept seven hens in contact with tuberculous birds in an uncleaned pen but failed to obtain infection. Later tests in Avhich he kept healthy hens in close contact with badly diseased birds failed to show the disease after five months. Hastings, Halpin and Beach (41) obtained nine hens from a diseased flock. These were placed with seven healthy birds in a small uncleaned room for a month. After 10, 26, and 46 days three of the diseased birds succumbed, the remaining six were killed one year later and all but one showed the disease. One of the originally healthy hens was killed after eight months and showed tuberculous lesions. The others were killed after one year and an examination showed that two of the six Avere tuberculous.
52
POULTRY
SCIENCE
(To Be Concluded in t h e Next Issue)
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 10, 2015
time. Maffuchi (43), however, showed that infected embryos would continue to develop. Artault (44) made a study of the bacteria in eggs and by rabbit inoculation found the tubercle bacillus to be present in two of 25 eggs. Gartner (45) injected pure culture of this organism into 12 female and one male canary birds. From these birds he got nine eggs. The egg material was injected intraperitoneally into guinea pigs and two were found to contain the tubercle organisms. In a second experiment he injected 25 canary birds. Prom these he obtained 24 eggs, two of which were found to eontain the organism. Koch and Eobinowitsch (40) injected tubercle bacilli into 32 eggs. Fourteen were infected with avian type, eleven with human type and seven with bovine type. Bight chicks were hatched from these eggs. Of these one had been infected with the avian type, three with human type and four with bovine type. The chick infected with avian type died in 75 days with generalized tuberculosis. The chicks from the eggs infected with human type were killed after 133 days but no trace of disease could be found. Of the four chicks hatched from the eggs infected with the bovine type, one died in 33 days with tuberculosis of the caecum, one died at 137 days with tuberculosis of intestines and liver and two were killed but showed no disease. Baumgarten (46) injected several eggs with a culture of avian type but only two hatched. One of the chicks died in four months with generalized tuberculosis. The second died in four and one-half months of tapeworm infestation, but showed a few lesions of the disease in the peritoneum, liver and spleen.