The World Health Organization is rushing an oral cholera vaccine and other essential treatments to Haiti to try to prevent an epidemic of the fatal disease among victims of Hurricane Matthew. WHO cholera expert, Dominique Legros, warns that the risk of cholera increasing is great because heavy flooding left by Hurricane Matthew is likely to contaminate the water. In Haiti, Interim President Jocelerme Privert said 13 people have died of cholera since the hurricane hit, CNN reported. Rene Domersant of the Haitian Health Ministry said there are 128 confirmed cases of cholera and 160 suspected cases in the country, UPI reported. Cholera is transmitted through contaminated water or food. It causes diarrhea and vomiting that can lead to death through dehydration. “The top priority clearly for those people affected by the hurricane is to give them access to safe water,” Legros said. “That is the only way we can control cholera in the long term in Haiti and elsewhere." For those who are sick with cholera, the top priority is to treat them and give them access to treatment, he added. It is particularly concerning, he said, because 35 of Haiti’s 197 health care facilities were damaged by the hurricane. The United Nations estimates more than 2 million people have been affected by the disaster, with 1.4 million in need of humanitarian assistance. To keep a possible cholera epidemic in check, the World Health Organization is sending 1 million doses of oral cholera vaccine to Haiti. Legros says there are two options for using the vaccine. “We can use it the classic strategy with two doses, therefore, we would cover half a million people,” he said. “We can also go for a single dose campaign, which will be easier to implement and that would add coverage for 1 million people, twice as many. The problem with the single dose campaign is that the protection is going to be relatively short.” Legros noted that the single dose route would protect more people during the rainy season from November to January, which is the peak of cholera transmission in Haiti. He says he will travel to Haiti this week to discuss the best course to take with WHO’s partners and the government. U.N. Nepalese peacekeepers introduced cholera into earthquake-devastated Haiti in 2010. Since then, the World Health Organization reports there have been nearly 800,000 cases of this fatal disease, including 9,300 deaths. This year, the U.N. agency reports nearly 30,000 cholera cases in Haiti.