Surveillance for Vibrio cholerae in environment and food in Beijing,2004-2013

Objective To understand the contamination status of Vibrio cholerae in environment and food in Beijing, and provide evidence for the prevention and control of V. cholerae infection in human. Methods From 2004 to 2013,Six types of samples, including surface water, swimming pool water, aquaculture water, aquatic products, cooked food and others, were collected monthly from 16 districts and counties in Beijing. V. cholera was cultured by using these samples and a descriptive epidemiologic analysis was conducted. Results The positive rates of V. cholerae were high in aquaculture water samples(1.16%, 44/3808) and other type samples(1.48%, 61/4135). The detection results were all negative in swimming pool water samples. The environmental V. cholerae positive samples were mainly distributed in suburb around urban area. The detection rates in bullfrog and soft-shelled turtle were high. A small number of CT toxin positive V. cholerae samples were identified, accounting for 9.09%(5/55) of the total and all of these samples were from swabs of aquatic products. Since 2007,less cholera outbreaks occurred in environment. Contamination of V. cholerae O139 tended to decrease, while the contamination of V. cholerae O1 Inaba serotype was in increase. Conclusion In Beijing, the contamination of V. cholerae is relatively mild and the CT toxin negative strain is predominant, indicating the lower risk to human health.