EPIDEMIOLOGY OF CHOLERA IN DELHI - 1992

Cholera is endemic in Delhi and is a highly seasonal disease. Suspecte d cholera cases are referred to Infections Diseases Hospital, Delhi. R ectal swabs from 2783 cases were bacteriologically examined during 199 2, out of which 1075 were found to be positive for Vibrio cholerae O1 biotype El Tor. First isolation was made on 3 April and the last on 14 December. About 87 per cent isolations were made between May and Sept ember, which are summer and monsoon months in Delhi. Detailed epidemio logical information was collected for about 198 cases of diarrhoea out of which 103 were confirmed cases of cholera. Half of these cases occ urred in children below 10 years of age. The other major group affecte d was adult females, especially housewives. All the cholera cases occu rred in those who were illiterate or educated up to primary level. Imp ortant risk factors were: contact with person having similar illness, storage of water in wide-mouthed containers, use of glass or mug to dr aw water from containers, absence of sanitary latrines and habit of wa shing hands with water alone after defecation, before cooking and eati ng food. About 30 per cent cases had access to piped water supply whic h was found safe in Delhi during 1992. The findings suggest that the h ygienic practices were more important than contaminated water sources for transmission of cholera in Delhi during the year 1992.