Authorities in Haiti say 544 people have died in an outbreak of cholera, while the death toll from Hurricane Tomas has reached 20.
The health ministry says more than 8,000 people have been hospitalized for cholera in recent weeks.
Hurricane Tomas lashed Haiti with winds and rains as it passed to the west of the country late last week, triggering flooding and mudslides. Several people remain missing.
The Haitian government and humanitarian groups rushed to evacuate at-risk Haitians who have been living in makeshift tents, but many resisted. Hundreds of thousands of people have been living in the crowded, squalid camps since the January earthquake that destroyed their homes and killed some 250,000 people.
The U.N. has warned that polluted floodwaters and unsanitary conditions could worsen the cholera outbreak, which has been centered in the Artibonite region north of the capital. Aid groups say the tent cities face a high risk for diseases because of the poor sanitary conditions.