Understanding the Cholera Epidemic, Haiti

After the devastating outbreak of cholera in Haiti in mid-October 2010, several hypotheses have emerged regarding the origin of the outbreak. Some articles and media reports pointed to the United Nations peacekeepers from Nepal as the source. Piarroux et al. drew a similar conclusion from their epidemiologic study (1). Nepal did experience an outbreak of cholera during August–October 2010, in which 72 cases of infection with Vibrio cholerae O1, serotype Ogawa, were confirmed, mostly among young adult males. The cases peaked from mid-September to early October (Figure; Figure A1), and no deaths occurred. Despite this similarity in timing, I believe several points need to be considered before a firm conclusion is reached.