Haitian officials said on Saturday that an outbreak of cholera had killed at least 13 people in southwest Haiti in the wake of Hurricane Matthew.
Government teams fanned out across the southwestern tip of the country to repair treatment centres and reach the epicentre of one outbreak.
Six people died of cholera in a hospital in the town of Randel, which is inland on the peninsula, and another seven died in the coastal town of Anse-d'Ainault on the western tip, the officials said, likely as flood waters mixed with sewage.
According to a Reuters tally of numbers given by local officials, the storm took the lives of nearly 900 people in Haiti, many in remote towns clustered near the headland.
The official death toll stands at 336 because officials must visit each village to confirm the numbers.
Cholera is spread through contaminated water and has a short incubation period, which can lead to rapid outbreaks. It also causes severe diarrhoea and can kill within hours if untreated.
"Randel is isolated, you must cross water, you must go high in the mountains, cars cannot go, motorcycles cannot go," said Eli Pierre Celestin, a member of the team that fights cholera for the Health Ministry.
"There are nurses but no doctors," he said, concerned that cholera would spread due to lack of hygiene and as ground water moves due to rain and floods.
— UNICEF Haiti (@UNICEFHaiti) October 7, 2016
Dr Donald Francois, head of the Haitian Health Ministry's cholera programme, said 62 others were sick with cholera as a result of the storm.
Port Salut recorded its first cholera case in seven months on Saturday, and two more suspected cases were brought by ambulance to the town's clinic.
US medical aid group AmeriCares dropped off supplies at the clinic, the only building standing among a group of shops flattened by the storm, before trying to reach Port-a-Piment further up the partially-flooded coastal road where the storm made landfall. A larger outbreak is suspected there.
United Nations peacekeepers accidentally introduced cholera to Haiti after the 2010 earthquake in the country, and it has since infected hundreds of thousands of people and killed more than 9,000 of them.
The aid group Doctors Without Borders has scrambled teams by helicopter to southern Haiti to respond to cholera cases.
— Doctors w/o Borders (@MSF_USA) October 8, 2016
Clifford Gauther, the Health Ministry's director for Haiti's Sud Department, said cholera treatment centres, many made of metal sheeting, were destroyed by the hurricane. The ministry was rebuilding them.
Before the hurricane struck, the Central Emergency Response Fund released a loan of $8 million to the United Nations Childrens' Fund, to ramp up the response to the worsening cholera epidemic in Haiti.
"In 2016 almost 27,000 cholera cases have been reported in Haiti, and over 240 people have died. Hurricane Matthew is feared to significantly worsen the situation and increase the risk of a larger outbreak," CERF said in a statement on Friday.