Scientists say Haiti cholera cases underestimated

CMC

Thursday, March 17, 2011

BOSTON, USA (CMC) — A new study by researchers at Harvard School of Public Health here suggests that United Nations' agencies have underestimated the number of cholera cases in Haiti.

In an article published in the British medical journal, The Lancet, the authors of the study reveal that their mathematical modeling data predicts nearly 800,000 cases and over 11,000 deaths from the cholera outbreak in the French-speaking Caribbean Community country.

The UN agencies had estimated only 400,000 cases since the first case was discovered in October last year. So far more than 4,000 people have died from the water-borne disease..

However, the researchers say that by combining the available disease control strategies of improved access to clean water, oral vaccination and expanded antibiotic use, thousands of further deaths could be prevented.

The model also shows that a recent decline in cases of cholera in Haiti is not the result of successful interventions currently being employed, but rather the natural course of the epidemic.

"Although worldwide estimates of the epidemic at present are based on the assumption that the epidemic will attack four per cent of the population, this assumption is essentially a guess--based on no data, and ignoring the dynamics of cholera epidemics, such as where people acquire the infection, how they gain immunity, and the role of human interventions such as water allocation or vaccination", said Dr Jason Andrews, a research scientist at Harvard School of Public Health and one of the lead authors of the study.

The researchers said to more accurately predict the spread of cholera in Haiti and aid the allocation of resources, they have developed a series of mathematical models taking into account existing disease trends and mechanisms of transmission and immunity.

The model, developed from previous models of cholera transmission and fitted with daily incidence data from each province in Haiti from October 31, 2010 to January 24, 2011, was designed to project the future course of the outbreak and simulate the potential impact of three interventions --clean water, vaccination, and enhanced antibiotic distribution, the researchers said.