An epidemiological investigation of a cholera outbreak in peri-urban slum settlements of Gujarat, India

BACKGROUND: Cholera is an acute diarrhoeal disease caused by consuming contaminated food and water. The burden may remain underreported due to several issues like the low capacity of epidemiological surveillance systems, laboratory testing facilities, and socioeconomic disparities in urban slums. The disease has very short incubation period resulted in quick clustering of cases. AIM: A thorough outbreak investigation was carried out with the objective of strengthening the surveillance activity, finding out the sources of infection, and recommending necessary actions to control the outbreak immediately. METHODS: An unusual increase in cases of diarrhoea was reported in slum area of Kalol town during the first week of July 2021. The stool samples were taken and investigated for confirmation and declaration of the outbreak by the Rapid Response Team. Time, place, and person distribution were carried out to generate a hypothesis and provide an immediate public health response to contain the outbreak. This study was conducted during the emergency public health response, no ethical approval was sought before the survey. RESULTS: The cholera outbreak was confirmed when three out of five stool samples were positive for the bacterium V. cholerae O1 biotype El Tor serotype Ogawa. The overall attack rate and case fatality rate were 3.6% and 1.1%, respectively. The leakages caused the mixing of drainage water with the drinking water supply, which could be the possible cause of outbreak. CONCLUSION: The early identification and management of the cases, source reduction, health education on water chlorination, and hand hygiene were initiated based on our recommendations, which controlled the present outbreak.