|Doctors Without Borders said the increase in the number of patients with cholera-like symptoms was worrying [AFP]
Health officials in Haiti have confirmed the first case of cholera in one of the earthquake survivors' camps set up in the capital, Port-au-Prince.
The development heightened fears that the disease, which has already claimed hundreds of lives, could spread rapidly among thousands of people living in the cramped camps - the perfect breeding ground for cholera.
Al Jazeera's Cath Turner, reporting from Port-au-Prince, said the first confirmed case was a 26-year-old woman.
"Last Saturday the authorities were alerted about a 26-year-old woman ... with acute diarrhoea. She was isolated in her tent and treated for suspected cholera," she said.
"She was then moved to a treatment clinic where she was in isolation again and has now recovered. Her tent, her toilet and the area she was living in was sprayed and she is now back living in the tent and [is] no longer a risk to the area.
"Now, in the last hour, the national laboratory, which is attached to to the Haitian ministry for health, rang the camp manager and confirmed that it was cholera. That's the first incident we've heard of a cholera confirmed case ... That woman was a group of six suspected cases. That's the first one that has come back positive. We're still waiting for results on the other five of the group."
'Large urban slum'
At least 600 people have been killed by cholera since the first cases were confirmed about two weeks ago. More than 7,000 others are receiving treatment.
Haitian authorities have been warned to prepare for the worst if cholera spreads in Port-au-Prince, which is still largely in ruins after the January 12 earthquake that killed more than 250,000 people. Hundreds of thousands of people still live in camps in the capital.
Cath Turner reports on a camp in Port-au-Prince,where thousands of people are living in unsanitary conditions
"Port-au-Prince is a large urban slum with very poor water and sanitation conditions. This is ripe for the rapid spread of cholera. We have to be prepared for it," Jon Andrus, a senior UN health official, said.
Doctors Without Borders (MSF), a medical charity, said it was extremely concerned at the increase in the number of patients with cholera-like symptoms in the capital.
Haiti suffered yet another tragedy last Friday when Hurricane Tomas triggered rains and flooding that left at least 20 people dead.
Doctors and aid groups were rushing to set up cholera treatment centres across the capital and said they were expecting a "large upsurge in numbers".
"We expect transmission to be extensive and we have to be prepared for it, there's no question," Dr Jon Andrus, deputy director of the Pan-American Health Organisation, said on Tuesday.
"We have to prepare for a large upsurge in numbers of cases and be prepared with supplies and human resources and everything that goes into a rapid response."
Threat to the nation
Haiti's health ministry said on Tuesday the disease had become a threat to the entire nation of 10 million people.
"Now it is our duty as citizens to help solve this problem, which has gone from being an urgent humanitarian matter and gone to the level of national security," Dr Gabriel Timothee, the ministry's executive director, said during a televised news conference.
The disease, spread when infected faecal matter contaminates food or water, is treatable mainly by rehydrating the sick with safe water mixed essentially with salt, sugar and potassium.
Antibiotics also are used sometimes.
But decades of failing and often regressing infrastructure - wracked by political upheaval, unbalanced foreign trade, a 1990s embargo and natural disasters - have left millions of Haitians without access to clean water, sanitation or medical care.