Prevalent Types of Cholera Vibrio

\\ Sir,?Out of 250 cases of cholera (diagnosed on clinical grounds) in 1941 Vibrio cholerw Inaba sub-type were isolated in 71 and V. cholerw Ogawa sub-type were isolated in 76 and no vibrios seen in 58. Two hundred and twenty-six cases were examined in 1942 and V. cholera} Ogawa were found in 70 and V. cliolcrw Inaba in 45, and no vibrios were seen in 111. This 45 includes 9 cases out of 14 evacuees from Burma. Two hundred and sixty-six cases of cholera were examined in 1943 (up to 10th July, 1943) and V. cholerw Ogawa were isolated in 154 and no Inaba sub-type could be seen at all this year. No vibrios were found in 112. Eight hundred and fourteen samples of stool were examined from these 266 cases. A consideration of these findings is important in the preparation of prophylactic vaccine. V. cholerw Ogawa only has been found in 1943 and isolations of V. cholera; Inaba have been gradually declining since 1941. So V. cholerw Ogawa should be in greater proportion in the vaccine and only a small amount of 1". cholerw Inaba may be added to the vaccine for inoculations in Calcutta. I had been to Madras in March this year, and found that only V. cholerw Ogawa were isolated during cholera epidemic there this year. In future, too, great care should be taken to type the vibrios isolated during epidemic and to supply the appropriate proph3'lactic vaccinc. S. K. SEN GUPTA, M.B., D.T.M.