Study on Haitian cholera epidemic reignites controversy

A recent study pointing to a more complex set of causes behind the cholera epidemic in Haiti has reignited controversy over who deserves to be blamed for spreading the disease.

The study, conducted by a University of Maryland cholera expert and published in the journal Proceedings of the National Academy of Sciences, challenges the current belief that United Nations peacekeepers from Nepal alone caused the outbreak that has sickened over half a million people and killed at least 7,000, according to

Rita Colwell, the report's author and a former director of the U.S. National Science Foundation, argues that existing analyses of the epidemic cannot point definitively to a single source as a cause. Colwell's research found several factors, including a strain of nontoxic cholera that could have existed prior to the peacekeeper's arrival, that potentially contributed to the spread of the disease.

The report noted that a confluence of unique environmental factors occurring in 2010 enabled the bacteria to surface and take hold among the Haitian population. Immediately prior to the onset of the epidemic, Haiti was hit by a very hot summer season, followed by a hurricane and then a massive earthquake, reports.

Anomalously high air temperatures in combination with the destruction of the country's sanitation systems and flooding caused by the hurricane created a situation that would favor an outbreak of a waterborne bacterial illness.

French epidemiologist Renaud Piarroux, who conducted a study that "strongly suggests" the U.N. peacekeepers are to blame, discounted Colwell's findings. Piarroux is currently writing a book on the source of the epidemic.

"The perfect storm is a perfect lie," Piarroux said, reports. "This is not a scoop. It means nothing."