Cholera outbreaks in South and Southeast Asia: descriptive analysis, 2003-2012

We conducted descriptive analysis of available information regarding the epidemiology of cholera outbreaks in South and Southeast Asia during 2003-2012. Information from 58 articles, 8 reports, and World Health Organization databases were analyzed. Overall, 113 cholera outbreaks were studied in South and Southeast Asia during the past 10 years. The majority of the outbreaks (69%) occurred in Southeast Asia, including India (52%). The highest number of outbreaks was observed in 2004 (25.7%). The most commonly identified source was contaminated water: however, in some countries, the spread of cholera was facilitated via contaminated seafood (e.g., Myanmar, Thailand, and Singapore). Several genotypes and phenotypes of Vibrio cholerae, the causative agent of cholera, were identified in the outbreaks, including V. cholerae O1 El Tor (Ogawa and Inaba) and V. cholerae O139. The emergence of multidrug-resistant V. cholerae strains was a major concern. Cholera-related mortality was found to be low across the outbreaks, except in Orissa, India (currently Odisha) during 2007, where the case fatality rate was 8.6%. Potential limitations included underreporting, discrepancies, possible exclusion of nonindexed reports, and incomprehensive search terms. The provision of safe water and proper sanitation appear to be critical for the control of further spread of cholera in South Asian and Southeast Asian regions.