Epidemiology of Vibrio cholerae 0139 with special reference to intrafamilial transmission in Calcutta

Abstract

A total of 27 families of hospitalised patients (index case families) suffering from acute watery diarrhea caused by Vibrio cholerae 0139, and 14 neighbourhood families were bacteriologically screened for 4 consecutive days to determine the extent of V. cholerae 0139 infection amongst healthy contacts and other suspected vehicles of transmission at the intrafamilial level. V. cholerae 0139 was isolated from faeces of 14.6% of healthy contacts in index case families as compared to none in neighbourhood families (P = 0.002). The organism could be recovered from 3.7% of handwashings of contacts of index cases and also from stored drinking water (8.0%), open well water (28.6%), flies (3.8%) and pond water (25.0%) used by the index case families and none from neighbourhood families. The large number of asymptomatic infected persons indicate an epidemiological similarity to that of eltor cholera. The organisms may be carried on hands and may act as a potential source of infection to other inmates through contamination of stored drinking water, open wells etc. The results will be useful in formulating strategies for intervention of transmission of V. cholerae 0139 at the community level.