Wednesday, May 4, 2011
Are researchers responsible for cholera deaths in Haiti?
Cholera outbreak that began in Haiti in October 2010 had affected more than 200,000 people and resulted in more than 4000 deaths. Since then, cholera has been reported in neighboring Dominican Republic and also in U.S. and Canada.
Since Haiti was free of cholera for nearly 50 years, the immediate question was how the disease suddenly appeared in Haiti (although cholera outbreak occurred in Latin America in 1991, it did not reach Haiti at that time). A mission report by Renaud Piarroux, a French epidemiologist and a renowned cholera expert, had no doubt that the organism was imported from South Asia, most probably by U.N. peacekeepers from Nepal. The unpublished mission report by Renaud Piarroux can be read at http://www.ph.ucla.edu/epi/snow/cholera_haiti_piarrouxreport.html
The reasons why the cholera outbreak in Haiti is proposed to be a case of imported one are
-Nepal and other South Asian countries are endemic to cholera and cholera outbreak had occurred in the capital city of Kathmandu, Nepal on September 2010
-UN peacekeepers from Nepal arrived in Haiti between October 8 and 15, 2010
-The first confirmed case of cholera showing the symptoms was reported on October 14, 2010
- As per Dr. Ralph Frerichs, “taking into account an incubation period of 2-3 days, the two events (i.e., arrival of troops and onset time of initial case) were closely related in both place and time”.
- The first patients in Haiti used to drink water from a tributary of the Artibonite River flowing just below the base of United Nations Stabilization Mission, where the peacekeepers were staying
- People reported that a nauseating liquid poured from pipes from the base at the time the outbreak occurred
- The Haitian V. cholerae isolate was found to be closely related to the variant strain predominant in South Asia and was distinct from those circulating in Latin America and U.S. Gulf coast (Chin et al. 2011).
Nepal Government and the U.N. were quick to reject the findings in the report. So were some cholera researchers like Dr. Rita Colwell, University of Maryland. According to Dr. Colwell, the organism was present in the aquatic environment of Haiti already and the outbreak could be related to climate patterns especially to La Nina. She commented “I think it’s very unfortunate to look for a scapegoat. It is an environmental phenomenon that is involved. The reason we don’t know [the catalyst] is because the medical community is not receptive to climactic causation or correlation.”( http://www.circleofblue.org/waternews/2010/world/hold-cholera-in-haiti-the-climate-connection). However, as per Dr. Matthew Waldor of Harvard Medical School, “the idea that a microbe so closely resembling a South Asian strain would emerge in Haitian waters is “frankly absurd”
For scientists who had spent 3-4 decades in cholera research and who had received millions of dollars of grants towards their research on the environmental and climactic patterns in cholera outbreak, the embarrassment is understandable and evident. Now the medical community is blamed for not being receptive to the climactic causation. However, if the medical community can not be convinced even after 3-4 decades of research, after utilizing millions of dollars, the problem lies elsewhere.
From 1980s onwards, the focus of cholera research almost completely shifted to environmental and climactic factors and ignored human-associated factors even though there were sufficient evidences for the latter. Had the researchers given the deserved importance to human factors, they could have warned the scientific community and U.N. effectively about the possible cholera outbreak in Haiti and thus could have averted thousands of deaths. Misinterpretation of scientific data, thus, results not only in the wastage of money, but can also cost lives. This is another lesson Haiti has taught us, but only time will tell whether we had learned anything.
Next- Some interesting quotes on the outbreak of cholera in Haiti
Chin et al. (2011). The origin of the Haitian cholera outbreak strain. N Engl J Med. 364(1):33-42.