The United Nations humanitarian office reports that 9,971 cases of cholera have been confirmed in Haiti, and 643 people have died from the disease.

The Associated Press reported earlier this week that the epidemic has spread into Port-au-Prince, where close to half of the city’s nearly 3 million residents are living in tent camps erected for those left homeless after the January earthquake. Conditions in the camps have deteriorated as a result of Hurricane Tomas, and many fear the disease will spread quickly through Port-au-Prince’s camps and slums.

Haitian healthcare workers and humanitarian groups have stepped up their efforts for both prevention and treatment. They’re urging residents to wash their hands regularly and thoroughly cook all food, and nearly 500,000 water purification tablets are being distributed. Fifteen cholera treatment centers have been set up, and hospitals have been equipped to respond. Treatment is fairly straightforward: since cholera kills through diarrhea that leaves patients severely dehydrated, rehydration (orally and via IV) is the key, antibiotics can also be used to fight the bacteria.

Partners in Health and Doctors Without Borders are two of the organizations providing healthcare to Haitians (and accepting donations to fund their work), and both are posting updates from the field on their websites.