Reply to Mekalanos et al.: Genomic diversity of Vibrio cholerae

We reported non-01/0139 Vibrio cholerae prevalence in patients during the early weeks of the Haiti epidemic (1), to which Mekalanos et al. (2) responded. Cholera, a centuries-old worldwide scourge, believed to be caused only by toxigenic V. cholerae O1, in 1992 was shown to be more complex, when a non-O1 V. cholerae India/Bangladesh epidemic occurred. Non-O1/O139 strains are not routinely assessed (3), but recent studies show significant prevalence of non-O1/O139 infections, up to 30.4% incidence among hospitalized patients (4). We used highly sensitive methods to identify O1 and non-O1/O139 strains (1, 5), because methods used to culture V. cholerae O1 are indeed unreliable, particularly under makeshift conditions (2).