An outbreak of cholera has killed 13 people in the aftermath of a hurricane that left almost 900 dead, prompting fears of another epidemic in the developing nation.

Dozens are reported ill with the disease, with more deaths expected, amid concerns that international attention has waned.

In the wake of Hurricane Matthew, floodwaters have mixed with sewage to spread disease.

Cholera – which causes severe diarrhea and can kill within hours if untreated – is spread through contaminated water and has a short incubation period, which leads to rapid outbreaks.

The Haitian government said there would be three days of national mourning following Hurricane matthew.

Government teams fanned out across the hard-hit southwestern tip of the country to repair treatment centers and reach the epicenter of one outbreak.

Six people died of cholera in a hospital in the town of Randel, which is inland on the peninsula,

"Randel is isolated, you must cross water, you must go high in the mountains, cars cannot go, motorcycles cannot go," Eli Pierre Celestin, who fights cholera for the health ministry, told Reuters. "People have started dying."

"There are nurses but no doctors," he said, concerned that cholera would spread due to lack of hygiene and as ground water moved because of rain and floods.

The Aftermath of Hurricane Matthew Show all 14 1 /14 The Aftermath of Hurricane Matthew The Aftermath of Hurricane Matthew 11 October 2016 A woman illuminates her family with a candle as they sleep on the floor in a partially destroyed school used as a shelter after Hurricane Matthew hit Jeremie, Haiti Reuters The Aftermath of Hurricane Matthew 11 October 2016 Mist rises off the water as a flooded building is pictured after Hurricane Matthew passes in Lumberton, North Carolina, US Reuters The Aftermath of Hurricane Matthew 11 October 2016 Children sleep over metal sheets in a partially destroyed school used as a shelter after Hurricane Matthew hit Jeremie, Haiti Reuters The Aftermath of Hurricane Matthew 11 October 2016 People carry the coffin of a woman who died during Hurricane Matthew in Jeremie, Haiti Reuters The Aftermath of Hurricane Matthew 11 October 2016 Destroyed houses are seen after Hurricane Matthew passes Grande Cayemite, Haiti Reuters The Aftermath of Hurricane Matthew 11 October 2016 Clothes hang in an area destroyed by Hurricane Matthew in Les Anglais, Haiti Reuters The Aftermath of Hurricane Matthew 11 October 2016 A woman with cholera symptoms receives medical atention at the health center of Les Anglais, in Les Cayes in the southwest of Haiti Getty The Aftermath of Hurricane Matthew 11 October 2016 Residents line up for food after Hurricane Matthew in Anse D'Hainault, Haiti. Nearly a week after the storm smashed into southwestern Haiti, some communities have yet to receive any assistance, leaving residents who have lost their homes and virtually all of their belongings struggling to find shelter and water AP The Aftermath of Hurricane Matthew 10 October 2016 People sick with cholera receive medical assistance at Saint Antoine hospital in Jeremi, Haiti. According to the UN after hurricane Matthew the disease has spread EPA The Aftermath of Hurricane Matthew 10 October 2016 A woman and a child sit on a buckets amid the ruins of their home destroyed by Hurricane Matthew, in Jeremie, Haiti AP The Aftermath of Hurricane Matthew 10 October 2016 UN blue helmets load aid which arrived in US helicopters onto a truck for people affected by Hurricane Matthew, in Jeremie, southwest of Port-au-Prince, Haiti Getty The Aftermath of Hurricane Matthew 10 October 2016 A UN helicopter lands next to aid sent by the United States for the people affected by Hurricane Matthew, in Jeremie, southwest of Port-au-Prince, Haiti Getty The Aftermath of Hurricane Matthew 10 October 2016 A boat passes a church in Nichols, South Carolina. Nearly 1 million homes and businesses still did not have power Monday morning in the Carolinas after Hurricane Matthew AP The Aftermath of Hurricane Matthew 9 October 2016 Boats sit washed up on shore amongst the twisted docks at Palmetto Bay Marina damaged by Hurricane Matthew in Hilton Head, South Carolina AP

Port Salut, one of several beach towns ravaged by waves, wind and rain, counted 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.

Cholera was accidentally introduced to Haiti by United Nations peacekeepers after the 2010 earthquake and has since infected hundreds of thousands of people and killed almost 10,000..

The aid group Doctors Without Borders scrambled teams by helicopter to southern Haiti to respond to cholera cases.

Clifford Gauther, the health ministrys director for Haitis Sud Department, said cholera treatment centers, many made of metal sheeting, were destroyed by the hurricane. The ministry was rebuilding them.

Before the hurricane struck, the Central Emergency Response Fund (CERF) released a loan of $8 million (£6.4 million) to the United Nations Childrens' Fund, to ramp up the response to a 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.