Health officials warn that an outbreak of cholera spreading through rural Haiti is only going to get worse.
The disease has already killed about 200 people, and has sickened at least 2,000.
The outbreak has been centered mostly in the rural Artibonite region of the country, and many believe a contaminated river is the source.
Officials fear it will soon reach the capital, Port-au-Prince. Once there, it could easily spread through the unsanitary camps housing hundreds of thousands of people left homeless by an earthquake in January.
An influx of patients has overwhelmed medical centers. Reporters visiting the main hospital in the town of St. Marc say scores of patients are lining the floors and courtyard.
The United Nations says humanitarian agencies, rushing to contain the outbreak, are distributing 10,000 boxes of water purification tablets and hygiene kits in affected areas.
Cholera is a bacterial infection that is typically spread by contaminated water or food. Symptoms include fever, severe diarrhea, and vomiting. The disease is treatable, but without attention, it can kill within hours.
International health experts say this is the first cholera outbreak to hit Haiti in decades.