ERADICATION OF PULLORUM DISEASE 1931-32 37 



Table 13 shows data concerning all groups. The data include the number of 

 sparrows treated, amount of exposure, agglutination reactions, and necropsy 

 observations. 



Among the 42 sparrows exposed to infection, 21 were not tested. The sera 

 of 11 of the 21 tested birds contained agglutinins. 5. pullorum was isolated from 

 31 of the 42 birds necropsied. No reactors were detected among the controls 

 and 5. pullorum was not isolated. 



Discussion 



According to the experimental observations, S. pullorum proved to be patho- 

 genic for the guinea fowl, pheasant, pigeon, and sparrow. It appears that the 

 guinea fowl, pheasant, and especially the sparrow are less refractory to 5. pullo- 

 rum infection than the pigeon. Among the 11 guinea fowl exposed to infection, 

 1 succumbed to the disease and the majority of the others revealed an agglutina- 

 tion titer which would suggest established systemic infection. Even though 

 bacteriological findings were negative for S. pullorum at necropsy, this does not 

 necessarily prove that the organism was not present in the body. Unfortunately 

 it was impossible to retain the female guinea fowl longer than 12 weeks, due to a 

 lack of facilities. It is quite possible that, since ovarian development was ob- 

 served at the time of necropsy, the guinea fowl might have laid eggs at a later 

 time. In view of the fact that S. pullorum was recovered from the ovary, the 

 organism might have been eliminated in the egg if the ovary had become active 

 in function. 



The pheasant appears to be as susceptible to the disease as the guinea fowl. 

 While some pheasants showed a marked decrease in their agglutination titers, 

 others possessed strong titers that showed very little fluctuation. Among the 

 latter group, S. pullorum was recovered from 3 of the birds at necropsy. One 

 laid one infective egg. Hence it appears that pullorum disease manifests itself 

 in adult guinea fowl, pheasants, and chickens quite similarly. While the com- 

 plete cycle of infection has not been demonstrated in these birds, it does not 

 seem improbable that the disease may gain a stronghold in guinea fowl and 

 pheasant raising establishments, especially under suitable environment, and 

 cause serious losses. Persons engaged in the raising of such fowl should respect 

 this disease as a possible hazard to their success in the rearing of chicks from 

 these species. 



The pigeon appears to be quite refractory towards S. pullorum infection. 

 Clinical manifestations were observed only in some of the birds inoculated in- 

 traperitoneally. The production of agglutinins was slightly stimulated in those 

 birds exposed to infection by the oral and ocular routes. The one case in which 

 S. pullorum was isolated from the yolk material suggests that the infection 

 was established in the system even though the agglutination titer showed a 

 marked decHne. According to these findings, 5. pullorum possesses but slight 

 pathogenicity for adult pigeons. Whether similar findings would be observed 

 among squabs cannot be stated at this time and will require further investigation. 



It is evident that the sparrow cannot withstand an exposure to a relatively 

 small number of organisms. Death occurred within a week in the majority of 

 cases. S. pullorum was recovered from a large number of birds. In a number of 

 cases the organism was recovered some time after the last exposure, indicating 

 that the disease may follow a sub-acute or even a chronic course. Since sparrows 

 do not appear to be capable of tolerating light exposures of S. pullorum, it is 

 conceivable that these birds might become infected readily on premises where 

 the disease is found and migrate to a place where the disease is not prevalent, 

 thereby acting as disease disseminators. While naturally infected sparrows have 



