Investigation of the outbreak of typhoid in a village of Thar Desert Rajasthan, India.

BACKGROUND & OBJECTIVES Outbreaks of typhoid have been reported from Maharashtra, Bangalore, West Bengal and Pondicherry in India but rarely from Rajasthan. We investigated an outbreak of typhoid in a village of Thar Desert of Rajasthan. METHODS A retrospective cohort study was carried out during May-July 2007 in Varkana village, Pali district, Rajasthan, to identify the risk factor for disease. The information on outbreak was collected and then described in time, place and person characteristics to arrive at aetiological hypotheses. RESULTS There were 219 cases of typhoid in village. Attack rate was 104 cases per 1000 population. Maximum attack rate of 276 cases per 1000 population was noted in persons of 10-14 yr age group. Forty three serum samples were reported positive for Widal agglutination test out of 70 tested. Drinking of water from government overhead tanks was associated with disease significantly (RR= 11.1, 95% CI= 3.7-33). Two of the three water samples from government tanks were found positive for faecal contamination. INTERPRETATION & CONCLUSION The outbreak of typhoid in a village affected >200 persons of all age groups and both gender. Exposure to the drinking water from government tanks was found significantly associated with the disease. Preventive and control measures undertaken after analytical epidemiological study helped in terminating the outbreak.