Value of Conglutination Reaction. 



23 



positive cases with the Flexner organism. In addition, congluti- 

 nation was obtained with this organism in 50 per cent, of the cases 

 during the first four days of the disease. Reactions of conglutina- 

 tion with the Shiga type were absolutely and relatively fewer than 

 by the other methods, which would seem to indicate a more abso- 

 lute specificity for this reaction. The reaction, when present, occurs 

 usually in very high dilutions (up to 1-800) and is not to be con- 

 fused with agglutination, as it frequently occurs when agglutina- 

 tion is absent in dilutions of 1-20, and may fail to occur when 

 agglutinations are positive. Inasmuch as bovine serum contains 

 a normal agglutinin for the dysentery bacillus, it is necessary to 

 work with a preperation from bovine serum obtained by saturating 

 with dysentery bacilli or by separating out by dialysis the insol- 

 uble proteids which contain the conglutinin but not the agglutinin 

 (Streng). 



As complementary to this work on infantile dysentery, a num- 

 ber of convalescent cases of dysentery from the Danvers State 

 Hospital have recently been examined by Dr. M. M. Canavan 

 under our direction. Dr. Canavan found that in these cases which 

 had suffered from dysentery from one and a half years to 

 one month previously, the agglutination reaction was present 

 with the Flexner strain in 10 of 14 cases and with the Shiga 

 organism in 3 cases. The conglutination reaction was present 

 with the Flexner organism in the same number of cases (10) 

 although not in the same cases in which the agglutination was 

 positive. Conglutination reaction with the Shiga organism was 

 present in one case only. It is interesting to note that in one case 

 which had had an attack of dysentery one and a half years pre- 

 viously, the conglutination reaction was present with the Flexner 

 organism, although agglutination was negative. Agglutination 

 reactions had been obtained a month previously in this case with 

 both organisms in low dilutions. In 8 control cases from the 

 same institution no conglutination reaction was obtained with 

 either organism. 



We have recently considered this reaction as a means of diag- 

 nosis in typhoid fever. We have met with a number of technical 

 difficulties and for this reason are not able to recommend the reac- 

 tion as yet as thoroughly serviceable. Our findings, however, 



