Cholera’s link to Asia confirmed

In an epic tale of speedy detective work, Silicon Valley and Harvard University geneticists have determined that Haiti’s cholera matches the virulent South Asian version of the disease – proving that this unusually lethal strain of disease was introduced from outside the suffering nation.

The researchers call for global health officials to consider mass vaccination, not only to control the spread of the disease in Haiti, where 2,100 have died, but also to reduce the chance that this particularly deadly strain will spread throughout the Caribbean.

“It has implications for how we treat and track patients – and given the global nature of disease, how we prevent its spread,” said principal investigator Eric Schadt of Pacific Biosciences, in Menlo Park, Calif..

In less than 24 hours, Schadt and his team sequenced the entire genome of Haitian cholera, using a new tool to decode samples delivered to their doorstop by courier.

By the end of the next day, other strains of cholera were also sequenced and the team made a match, showing a close relationship between the Haitian strain and samples from Bangladesh.

Their triumph, announced Thursday in the New England Journal of Medicine, confirms the findings of a more limited analysis last month by the Centers for Disease Control.

It could aid efforts to build a vaccine against the epidemic, which is killing an average of 45 Haitians a day. Even more promising is the speedy tool’s future use against yet-unknown global outbreaks, perhaps involving bioterrorism.

Haitians accuse United Nations troops from South Asia of delivering the disease, because the first cases coincided with their arrival.

The outbreak has mystified doctors, because Haiti has been cholera-free for a century.