The cholera strain that is devastating Haiti likely originated from Southeast Asia, reports researchers from Boston and Pacific Biosciences. In the New England Journal of Medicine, the researchers describe using PacBio's single-molecule real-time DNA sequencing method to distinguish the cholera strain circulating in Haiti from others found in Latin America and the US Gulf Coast. Indeed, they report that the Haitian strain is "nearly identical to so-called variant seventh-pandemic El Tor O1 strains that are predominant in South Asia" and they add that "understanding exactly how this South Asian variant strain of V. cholerae was introduced to Haiti will require further epidemiologic investigation."
As our sister publication In Sequence points out, this study confirmed an earlier CDC finding, though its significance may be in the speed at which the study was done. There were two weeks between sample collection to the submission of the paper, and sequencing took about 48 hours. "It was definitely intense," PacBio's Eric Schadt tells The New York Times' Andrew Pollack.