Haitian officials Tuesday confirmed the first death from cholera in the ruined capital as the number of sick surged amid fears the outbreak will spread to the city's teeming refugee camps.
One person was said to have died in the sprawling Cite Soleil slum, badly hit in the January earthquake which left 1.3 million people homeless in the impoverished Caribbean nation of some 10 million people.
For the moment there has been no large scale outbreak of the disease in the capital, but "it's coming," warned health ministry chief of staff Ariel Henry.
Other isolated cases of cholera were also recorded in the city, which is dotted with hundreds of unsanitary makeshift tent cities many of which were flooded in heavy weekend hurricane rains.
A thousand more patients have flooded to the nation's hospitals and clinics for treatment, meaning more than 9,000 people have now been sickened by the disease which has claimed 583 lives, health officials said.
The cholera death was recorded in the St Catherine hospital run by the aid group MSF-Belgique, which has treated 115 people since October for acute diarrhea, officials said.
Three bodies were also found on the streets of Port-au-Prince, but it was not immediately clear what the people had died of.
Authorities fear cholera, which is spread by contaminated drinking water or foods, could infiltrate the dirty camps where hundreds of thousands of people bathe, wash and cook right next to each other.
"We are worried about Cite Soleil, where one death has been recorded," admitted Gabriel Timothe, director of the health ministry.
"There has also been an increase in the number of cases in other regions of the country," he added, calling the cholera outbreak a matter of "national security."
The Haitian capital has so far been spared a widespread outbreak, but Hurricane Tomas appears to have contributed to its arrival here after the storm-swollen Artibonite River -- the presumed source of the bacterium -- overflowed at the weekend.
The storm was just the latest in a series of heavy blows for Haiti in the wake of January's quake that killed 250,000 people and ravaged the capital.
Even in the best of times much of Haiti's population live in precarious conditions, vulnerable to natural disasters, after mountainsides have been stripped of trees to be used as fuel, increasing the risk of landslides.
Although easily treated, cholera has a short incubation period and causes acute diarrhea that can lead to severe dehydration and death in a matter of hours.
Meanwhile, aid groups worried about remote areas where residents do not have access to clinics or hospitals.
"Outside of the larger population centers, it is critical that smaller, dispersed communities are able to access treatment," said Kate Alberti, an epidemiologist working for Doctors Without Borders.
"We are very concerned about the spread of the epidemic in rural areas, where transport to existing health structures is difficult," Alberti said.