TEST FOR BACTEEIUM PULLORUM INFECTION IN FOWLS. 



la 



On June 26 all the 47 birds and 9 controls were- reinjected and ex- 

 amined 5 hours later. At this time every bird, including controls, 

 displayed a swelling varying in the different individuals from a 

 trace to five times the normal thickness. The observation merely em- 

 phasizes the fact of the occurrence of a nonsignificant swelling fol- 

 lowing injection with the diagnostic agent. 



At 24 hours 39 birds displayed swelling of the wattle varying from 

 a trace to enlargement to five times the normal thickness. Autopsy 

 revealed undoubted lesions in 30 of these, questionable lesions in 

 7, and no lesions in 2. Total agreement between the results of this 

 reading, the agglutination test, and autopsy findings occurred in 70 

 per cent of the birds tested. In two cases, or 4 per cent of the 

 birds, the positive readings by the agglutination test were not sup- 

 ported by the negative results of the intradermal test and the 

 autopsy. In 1 case, or 2 per cent, negative results of the intradermal 

 test were contradicted by the positive results of agglutination test 

 and autopsy. Thus, the results yielded by the first and second 24- 

 hour readings of the test on supposedly infected birds vary but 

 little. 



The results yielded by the test on the control birds were perfect, 

 as confirmed by the autopsy. The only two birds that displayed 

 traces of swelling proved on autopsy to be infected. 



The fact that the results of the agglutination test, intradermal 

 test, and autopsy are in complete agreement in 70 per cent of the 

 cases, coupled with the fact that the absolute diagreements are very 

 small, indicates that the two tests are equally accurate. 



The results obtained at the autopsy of the birds emphasize the 

 difficulty of determining a standard for comparison of the accuracy 

 of the two tests under trial. Thirty-one cases, or 64 per cent, were 

 found to possess unquestionable lesions consisting of the angular ova 

 characteristic of the infection. . All of the cases had given positive 

 reactions to one or both tests. In nine cases, or 10 per cent, the 

 autopsy was inconclusive in that there were present only very small 

 dark ova or cysts. Of these 9 questionable cases 3 had given ques- 

 tionable agglutination readings but positive intradermal reactions. 

 In two cases the agglutination and intradermal tests disagreed. In 

 four cases both tests had given positive results. 



SIGNIFICANCE OF SWELLING AS AN INDICATION OF A REACTION. 



In determining the significance in diagnosis of an edematous 

 swelling of a wattle one is confronted with the fact that in ail birds 

 such swelling occurs shortly after injection. The problem is to 

 determine the point of time after injection to read the test when 

 this preliminary swelling has disappeared, yet not too late to escape 



