An outbreak of Vibrio cholerae in Vikas Nagar, Chandigarh, India

Background : On 1 July 2012, a large number of cases of acute diarrheal episodes were reported in Vikas Nagar, Chandigarh. A rapid response team was sent to investigate this outbreak on 3 July 2012. Aim : To determine the reasons for the outbreak and to focus on the identification of a gap in the management of the epidemic by applying remedial measures in the Vibrio cholera outbreak in the Vikas Nagar area of Chandigarh district. Materials and Methods : A house-to-house survey of 2765 houses was performed with 20 teams of Auxillary Nurse Midwife ANM/Anganwadi workers. Information regarding age, sex, place of residence, occupation, date of onset and treatment history and laboratory finding were collected. Environmental investigation and laboratory investigation of the stool samples were also performed. As the study was conducted during an emergency response to the outbreak, and was designed to provide information to orient the public health response, ethical approval was not required. Remedial measures were implemented. Results : A total of 1875 patients reported to the various health facilities of the Vikas Nagar area with complaints of increased frequency of loose watery diarrhea and a few had vomiting episodes during the time period of 1 - 14 July 2012. Four deaths were reported. Three hundred eighteen (318) cases were found in the house-to-house survey of 2765 houses of the area. Twenty-six percent of the cases were in the age group of <5 years. Hospitalization was required in 12.9% of the cases, while 87.1% were managed in the Outpatient Department. Eight samples were found to be positive for Vibrio cholera El Tor Serotype, Ogawa in samples from the house-to-house survey. A coliform count of >1800 MPN/100 mL was reported from 10 water samples. Investigations revealed that the epidemic was waterborne. Leakages in the pipes were found at many places leading to mixing of water with drainage, and water samples collected from the houses of the cases were found to be positive for Vibrio cholerae. Conclusion : Among the identified gaps, delays in the initiation of the investigation of the epidemic and pipe leakages were the most important. In India, waterborne epidemics are usual occurrences during the year. In this scenario, proper monitoring of water sources, proper sewage disposal, sanitation measures and creating awareness among the people should be undertaken