Cholera cases in Haiti could be double U.N.'s estimates, study says

March 16, 2011|By Linda Shrieves, Orlando Sentinel

How bad is the cholera epidemic in Haiti?

According to a new study, the epidemic now has the potential to spread the disease to nearly 800,000 people— twice the earlier estimate.

The study, conducted at the University of California, San Francisco and Harvard Medical School, will be published this week in the journal Lancet. It predicts that Haiti's cholera epidemic could continue until November and be far worse than the United Nations' projections of 400,000 cases.

The U.N. estimates are critical, the researchers say, because those are used to determine how resources are allocated.

"The epidemic is not likely to be short-term," said UCSF medical resident Sanjay Basu, M.D., who conducted the study with Jason Andrews, M.D., a former UCSF resident, now a fellow at the Massachusetts General Hospital and Harvard Medical School. "It is going to be larger than predicted in terms of sheer numbers and will last far longer than the initial projections."

Aside from estimating the spread of the disease, Andrews and Basu also examined the possible impact of three ways public health authorities might curb the epidemic: providing clean water, vaccinating some of the population and widely prescribing antibiotics.

Although the notion of prescribing antibiotics to a larger portion of the population is controversial because of its expense, Basu said their analysis suggests that broader use of antibiotics could save thousands of lives this year in Haiti.

Cholera is spread through water or food that has been contaminated by human feces. Left untreated, cholera causes acute diarrhea and can be deadly within hours. The standard treatment requires doctors and nurses to rehydrate patients with salty liquids, known as oral rehydration therapy. When that strategy is used, 99 percent of victims survive.

Before last year's devastating earthquake in Haiti, no cases of cholera had been seen on the island for more than 100 years. Now the disease has reemerged as a major epidemic.

That has become the pattern with modern-day cholera epidemics, which usually pop up after natural disasters, such as earthquakes and hurricanes. Cholera outbreaks also have occurred in African refugee camps.


In October, the U.N. projected that 200,000 people would eventually become infected, and then two weeks later it doubled that projection to 400,000.

According to Basu, however, the U.N. made its estimate based on the assumption that the disease would infect 2 percent to 4 percent of Haiti's population of 10 million people. Basu and Andrews said the U.N. estimates did not incorporate existing disease trends or take into account major factors, such as where water was contaminated, how the disease is transmitted or even human immunity to cholera.

Using data from Haiti's Ministry of Health and other sources, Andrews and Basu made a more sophisticated model of the spread of disease in several Haitian provinces. The results led them to predict that 779,000 Haitians would contract the disease and about 11,100 would die in the next eight months.

Using their calculations, they estimated that if health officials could reduce the number of people drinking contaminated water by only 1 percent, they could potentially prevent 100,000 cases of cholera and 1,500 deaths.

Vaccinating about 10 percent of the population would spare about 900 lives. The study also predicts that extending the use of antibiotics more widely would prevent 9,000 cases of cholera and 1,300 deaths.

The beauty of antibiotics, Basu said, is they not only help the person who received them, but they reduce the transmission of the disease to others. or 407-420-5433

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