22 



Scientific Proceedings (36). 



During the past summer the matter was thoroughly considered 

 by one of us (Lucas) in collaboration with Drs. Schorer and Fitz- 

 Gerald in a comparative study which was made of methods of serum 

 diagnosis in acute bacillary dysentery in infants. In this series of 

 cases, shortly to be reported in full, a bacteriological examination 

 was made of the stools for the presence of one or more types of 

 Bacillus dysenterise and a comparative study of the reactions of 

 agglutination, fixation, and conglutination made with the serum of 

 each case, and usually at intervals in the course of a given case. 

 From 45 cases of infantile dysentery, dysentery bacilli were iso- 

 lated in 84.4 per cent, and in 35 of these bacteriologically positive 

 cases, mannit fermenting organisms alone were present. In every 

 case the three reactions with the serum were tested both with a 

 mannit fermenting (Flexner) and a mannit non-fermenting (Shiga) 

 strain of the dysentery bacillus. Positive reactions with the Flex- 

 ner strain were much more frequent than with the Shiga strain ; 

 this may be due not only to a direct relation of the organisms con- 

 cerned in producing the infection, but also, in all probability, to a 

 greater susceptibility of the Flexner organism to the action of 

 serum. Fifteen control cases which gave no evidence of having 

 suffered from dysentery were also studied both bacteriologically 

 and from the standpoint of serum diagnosis. 



A positive reaction of agglutination was obtained with the serum 

 of one control case to the Flexner organism, but in none of them 

 to the Shiga organism. A positive agglutination reaction with 

 the Flexner strain was obtained in 55.5 per cent, of the positive 

 cases ranging from 9 per cent, during the first four days of the 

 disease, to 75 per cent, in the third week. In about half as many 

 cases a reaction was obtained with the Shiga organism. Fixation 

 reactions were obtained with the Flexner, but not with the Shiga 

 strain in over a quarter of the control cases (28.5 per cent.). The 

 reaction occurred with both Flexner and Shiga organisms about 

 equally in from 50 to 60 per cent, of the positive cases subsequent 

 to the first week. No positive conglutination reaction was ob- 

 tained in control cases, although in a few instances a reaction in a dilu- 

 tion of 1-40 did occur which was arbitrarily chosen as the limit of a 

 doubtful reaction, beyond which a reaction was called " positive." 

 The conglutination reaction appeared in 63.1 per cent, of the 



