XII, B, 2 Crowell and Johnston: Cholera Cases 97 



three days, and the agglutinability was tested each time. After 

 forty transfers, 8 (6 from fasces of cholera carriers and 2 from 

 cholera cases) of these strains showed prompt agglutination in 

 dilution of 1 : 500 of an immune serum by the microscopic method 

 and up to 1 : 4,000 by the macroscopic method. 



Of these strains but 5 held this apparently acquired property 

 of agglutination for any length of time, the other 3 losing it after 

 cultivation for a period of two months. The strains which now 

 agglutinate do not agglutinate as promptly as they did when the 

 property was first acquired about three months ago, but it is 

 still sufficiently quick to warrant their being classed as true chol- 

 era organisms on the basis of agglutination. 



The 30 strains studied resembled the true cholera vibrio mor- 

 phologically; all were monociliate and actively motile. All pro- 

 duced indol in peptone water and typical liquefaction in gelatin 

 and growth on Dieudonne. They differed in that, with the 

 exception of the 8 strains noted, none were agglutinated by a 

 high-titer cholera serum. When injected into guinea pigs they 

 did not produce agglutinin which agglutinated a standard chol- 

 era vibrio, except that 2 of the 5 strains, which acquired the 

 agglutinating property, did after this acquisition produce a se- 

 rum which partially agglutinated a standard vibrio in dilution up 

 to 1:100. 



CASES IN WHICH CHOLERA VIBRIOS WERE NOT FOUND 



Twenty-two cases in which cholera vibrios were not found are 

 included in this study on account of their clinical or anatomic 

 features. In 6 of these it is considered that the patients had chol- 

 era in spite of the fact that no vibrios were found in either the 

 intestine or gall bladder. This conclusion is based on the clinical 

 and anatomic features shown in Table VIII. Thirteen cases in 

 which there was some reason either clinically or anatomically to 

 suspect cholera were considered not to be cholera after all data 

 were available. Three cases which were clinically and anatom- 

 ically suggestive of being cholera were considered, in the light 

 of all the evidence, as probably not cholera, but a definite diag- 

 nosis on them is reserved. Greig, (20) in a very recent article, 

 states that in 72 out of 659 cholera cases examined no vibrio 

 was found. He also includes as cholera cases 51 other cases in 

 which only a choleralike vibrio was found. It may be noted that 

 in only 6 of the 221 cases considered cholera did we fail to find 

 the true cholera vibrio. Thirteen cases in our series, which were 

 suspected either clinically or anatomically of being cholera, were 

 eliminated from the list of cholera cases after careful consid- 



