56 CONTROL SERIES No. 63 



investigations and results in eradication, the macroscopic agglutination method 

 is the most efficient and the most extensively employed. Jones (52) was the 

 first to employ the macroscopic tube agglutination test for the detection of 

 infection in adult birds. Runnells and others (81) recommended the rapid serum 

 agglutination test for puUorum disease eradication. Investigations concerning 

 their relative merits have shown that properly trained persons can use the two 

 methods in the diagnosis of the disease with nearly the same degree of efficiency. 

 Bunyea, Hall, and Dorset (15) first described the rapid whole blood agglutin- 

 ation test. They employed a concentrated unpreserved five antigen and whole 

 blood. Blood smears were made upon a glass surface to which the test fluid 

 was added and mixed. A clumping of the bacteria within a certain time limit 

 was regarded as a positive reaction. The testing of whole dry blood was also 

 described. The authors found the results of this method to check quite closely 

 with the results of the tube method. Sawyer and Hamilton (84) reported that 

 an antigen prepared by a biological house for the whole blood test and placed 

 in the hands of a poultryman gave the following results: among 26 birds tested, 

 6 were diagnosed as reactors. Necropsy revealed that 13 birds contained S. 

 pullorum. Green and Robinson (38) reported the whole blood test very satis- 

 factory, although in some cases they found that birds with low titers might 

 escape detection. They stated that much more work is necessary before one can 

 determine the real value of this type of test. Bleecker (8) tested 2,159 blood 

 samples with the whole blood and tube methods. The whole blood method 

 was regarded as but shghtly less efficient. SchafTer and others (85) described 

 changes in the technique for the preparation of the antigen and the method 

 of conducting the test. They recommended a stained, preserved antigen and the 

 employment of a loop for measuring and conveying the fresh blood to the testing 

 plate. Various degrees of reactions which occur in the tube method were re- 

 ported. Reactions which occur within one minute after mixing the antigen and 

 blood were regarded as positive, whereas those reactions appearing more slowly 

 were considered as suspicious. The loop method was recommended to insure a 

 constant dilution of antigen and blood. Coburn and Stafseth (18) described the 

 preparation of stained antigen and technique for a whole blood test. Thirty 

 pullets were tested four times at two-week intervals with the whole blood and 

 tube methods. Twelve positive reactors were detected by the whole blood 

 method. S. pullorum was isolated from 11 of the reactors, of which 9 were posi- 

 tive to the tube method. Six birds which gave cloudy reactions were considered 

 doubtful. The authors did not state whether the two birds that did not react 

 positively to the tube method and from which S. pullorum was isolated, were 

 either doubtful or negative to the tube method. Hall and Bunyea (42) tested 

 206 hens with the whole blood and tube methods. An agreement of 91 per cent 

 was observed. Three dilutions (1:25, 1:50, and 1:100) were employed in the 

 tube method. Agglutination in the 1 :25 dilution was regarded as suspicious while 

 a reaction in the 1:50 or 1:100 was regarded as positive. The tube method 

 detected 143 reactors of which 114 fowls (80 per cent) at necropsy yielded S. 

 pullorum from the ovaries. The whole blood test detected 135 reactors of which 

 112 (83 per cent) at necropsy yielded S. pullorum from their ovaries. The two 

 reactors detected by the tube method and from which 5. pullorum was isolated, 

 reacted partially to the tube test and slightly to the whole blood test. In the 

 culturing of organs, only the ovary is mentioned. Cultures were incubated 24 

 hours. Welch (96) tested 5 flocks, ranging in size from 66 to 318 birds, with whole 

 blood and tube methods. Both the wet and dry whole blood methods were used. 

 The dry whole blood test appeared to be 90 per cent as efficient as the tube 

 method. By a comparative study of wet and dry whole blood methods in 6 

 flocks, he found the latter to be 94 per cent as efficient. The author states, 



