Outbreak of cholera due to contaminated pond water utilisation in a rural area of West Bengal, India, 2021

Background

On March 31, 2021, an outbreak of diarrhoeal disease was reported in Dangapara village of Purba Bardhaman district, West Bengal, India. The outbreak was investigated to estimate the magnitude, identify aetiological agents and source of infection, and guide prevention control measures.

Methods

We did an active search for case patients at Dangapara village. We excluded children under five years of age from the epidemiological analysis. We described the outbreak by time, place, and person. We conducted a case control study with 133 controls and 65 cases. Water samples from different sources and rectal swabs from case patients were collected and sent for laboratory investigations.

Results

We identified 95 case patients among 330 residents of Dangapara village (attack rate 29 %). Three stool samples were positive for Vibrio cholerae, and two pond water samples were contaminated with coliform organisms. Washing utensils [adjusted odds ratio (AOR): 69.8, (95% confidence interval (CI) 6.5–749.5)] and taking a bath in pond water [AOR: 3.4, (95% CI 1.2–9)] were associated with increased risk of illness. About 97% of cases were attributed to washing utensils in pond water. Washing hands before taking food was associated with a lower risk of developing disease with AOR: 0.1 (95% CI 0.03–0.33).

Conclusion

A cholera outbreak occurred among residents of Dangapara village due to theuse of contaminated pond water for washing utensils and bathing. Prompt management of cases and immediate discontinuation of pond water use stopped the outbreak.