The seemingly mysterious outbreak of cholera in Haiti — the first there since the 1960s — is not a mystery at all, said a University of Florida microbiologist who visited the nation in August.
Ali said the cholera bacteria probably have been present in the rivers and canals many Haitians use for drinking water for a long time. The germ multiplied to high levels — high enough to sicken more than 3,300 residents and kill 259 as of Monday — because conditions were perfect for incubation, he said. These include poor sanitation and the presence of thousands of residents displaced by January's devastating earthquake.
"Both highly contaminated inland water and estuarine water pose a great public health threat in Haiti. The situation is dire and needs urgent attention by either local and/or international authorities,'' Ali wrote in a report to UF colleagues shortly after returning from Haiti this summer.
His theory is far from definitive. Scientists at the Pan American Health Organization will not speculate on the source of the disease until they see firm evidence, such as a DNA analysis, said spokeswoman Donna Eberwine-Villagran.
It is also possible the disease came from outside the country, said Joia Mukherjee, medical director for the aid group Partners in Health. That was the case of a similarly sudden surge of the disease in Peru in the 1990s, the source of which turned out to be the holds of ships, she said.
Some cholera bacteria is present even in countries with good sanitation, Ali said. For example, the United States and Canada reported cases last year.
The concentrations are highest in warm water, which explains why this happened now rather than immediately after the January earthquake, he said. The bacteria also thrives in slightly salty water, especially when it has algae to feed on, Ali said.
The first cases were reported a week ago in St. Marc, a coastal city in the Artibonite region in west-central Haiti. Longtime residents had likely built up immunity to contaminants in the brackish water. Many of the estimated 300,000 people who moved to the Artibonite after the earthquake had not, Ali said.
Seventy-five percent of the people infected with the germ don't get sick, according to the Pan American health group. They serve as carriers and incubators, Ali said, and may harbor the large concentrations of bacteria needed to sicken others.
Once the disease develops, it causes diarrhea so severe that it can lead to death by dehydration in a few hours. This human waste, dumped in or near drinking supplies, can rapidly spread the disease, especially in the current, overcrowded conditions.
The outbreak, experts say, is Haiti's biggest public health threat since the January earthquake.
The number of new cases appears to have stabilized in the hardest-hit parts of the Artibonite, said Andrew Marx, a Partners in Health spokesman. But they have stabilized at a high level. About 600 people with cholera-like symptoms have been arriving daily at the government hospital in St. Marc.
The Ministry of Health and aid organizations have been spreading the word about the need for frequent hand-washing and the dangers of drinking contaminated water. Also, potable water trucked into settlement camps in Port-au-Prince may offer some protection to the especially vulnerable people who live there.
But five cases have already been reported in the capital and more are almost inevitable because of the number of people traveling from the Artibonite, Marx said. The organization is "hopeful, but not necessarily confident" that it can avoid a large-scale outbreak in the city, he said.
Dan DeWitt can be reached at (352) 754-6116 or firstname.lastname@example.org.