A RETROSPECTIVE ANALYSIS OF THE MADRAS EPIDEMIC OF NON-O1 VIBRIO-CHOLERAE NEW SEROGROUP O139 BENGAL

During the recent epidemic of cholera in Madras from October-December 1992, a total of 11,100 patients with acute secretory diarrhoea have b een admitted to the Communicable Diseases Hospital, Madras, when compa red to a total of 2,440 patients admitted during the pre-epidemic peri od studied between January . September 1992. A novel strain of non-01 V. cholerae was found to be the most predominant agent during the epid emic period. A representative sample of 84 non-01 strains isolated dur ing the epidemic-period were confirmed as V. cholerae non-01 and newly designated as serogroup 0139 at National Institute of Cholera and Ent eric Diseases, Calcutta. All 84 strains of non-01 were found to elabor ate cholera toxin (CT). Fourteen strains were also confirmed as serogr oup 0139 from our non-01 stock recovered during the pre-epidemic perio d. Of the 17,540 patients admitted during the post epidemic period, st udied from January 1993 - June 1994, 3.8 and 37.8 per cent patients we re infected by 01 and non-01 serogroup 0139 respectively. The new sero group 0139 continued to be the predominant isolate even during the pos t epidemic period.