International aid groups are trying to stop the the spread of cholera in Haiti's capital Port-au-Prince, where many earthquake survivors live in makeshift camps and filthy slums.
Cholera strikes so fast it is sometimes called the lightening disease. Without rehydration therapy, or antibiotics for severe cases, cholera can kill in a matter of hours. The disease causes acute diarrhea that can lead to severe dehydration.
Most of the more than one million Haitians displaced by a powerful earthquake last January live in tent cities around the capital, and waterborne cholera bacteria spread easily in unsanitary conditions where supplies are shared for cooking and washing. But unsanitary conditions in Haiti are not limited to these camps.
"Before this, Port-au-Prince for the most part, was a large urban slum with very poor water and sanitation conditions," noted Dr. Jon Andrus of the Pan American Health Organization, an arm of the World Health Organization. "This is ripe for the rapid spread of cholera. We expect transmission to be extensive."
Haiti's minister of health is calling the epidemic a national emergency. Nearly 10,000 people have been hospitalized since the outbreak began late last month.
Dr. Andrus says based on projections from an outbreak in Peru, some 270,000 people in Haiti may contract cholera. As the disease spreads in this initial outbreak, health care will be a challenge.
"I think the capacity to deal with the patients has been stretched but sufficient," he said. "We expect that patients will be treated in tents outside the walls [of hospitals]. That's something we are prepared to do."
Because cholera is spread through fecal contamination, poor hygiene and lack of sanitation, Dr. Andrus says the Pan American Health Organization has started a campaign to teach people about good hygiene.
"We've deployed communication experts that are working on community messages in the local Creole language to ensure that families receive such messages and understand them and it gets translated into behavior," Dr. Andrus
After the initial outbreak is under control, health officials will have to do some long-term planning.
"The bacteria has a foothold in the river system and in other sources of water and it will remain," he noted, "and it will be a challenge to control future spread."
One of the ways to keep cholera from spreading is to upgrade the sanitation system in Haiti.