A cholera epidemic in northern Haiti has claimed 135 lives and infected 1,500 people over the last few days, Claude Surena, president of the Haitian Medical Association, said Thursday.
"According to the results of the analysis carried out in the laboratory it is cholera," Surena told AFP, adding that a government statement on the health crisis was imminent.
The outbreak has so far not hit the capital, Port-au-Prince, ravaged by a 7.0 earthquake in January, which killed more than 250,000 people and left another 1.2 million homeless.
But "hospitals and medical centers in the regions are overwhelmed and numerous deaths have been registered," said Gabriel Timothe, director general of the Haitian health ministry.
"There are several hundred people in hospital, and we are evacuating a number of the sick patients to other centers."
Doctors contacted by AFP confirmed there had been deaths along the Artibonite river which crosses the center and north of the country.
According to local radio, most of the dead have been taken to hospitals in Saint Marc, about 100 kilometers (60 miles) north of the capital.
In Saint Marc, doctors had earlier told AFP that 26 deaths had been registered and more than 400 people hospitalized.
Eighteen people had also died in the town of Verette in the same region, while three had died in central Mirebalais where 100 were being treated in hospital.
"We have counted 27 deaths and 300 hospitalizations in the Drouin area," said doctor Jean-Robert Pierre-Louis by telephone from northern Haiti.
Haiti is still struggling to rebuild after the devastating quake, with hundreds of thousands of people crammed into makeshift tent cities in the ruins of the capital.
Many others fled the city to live with relatives in other towns across the impoverished Caribbean nation of about nine million people, the poorest country in the Americas.
Aid agencies have voiced fears for months that any outbreak of disease could spread rapidly due to the unsanitary conditions in the camps where people have little access to clean water.
International agencies have swung into action, mobilizing medical personnel to try to contain the spread of the disease and treat the sick.
"We are evaluating the situation on the ground with the international partners and the Haitian health authorities," said Fanny Devoucoux from the French aid organization Acted.
Cholera is caused by a comma-shaped bacterium called Vibrio cholerae, transmitted through water or food that has typically been contaminated by human fecal matter.
It causes serious diarrhea and vomiting, leading to dehydration. It is easily treatable by rehydration and antibiotics. But with a short incubation period, it can be fatal if not treated in time.
The World Health Organization says on its website that "cholera is an extremely virulent disease. It affects both children and adults and can kill within hours."
"The short incubation period of two hours to five days, enhances the potentially explosive pattern of outbreaks," it added.
The impoverished Caribbean nation has also been hit in recent days by severe flooding adding to the misery of those struggling to survive in the scores of tent cities now dotting the country.
Pandemic cholera last stalked the world in the 1960s, although the disease still erupts among refugees or in war zones where sanitation and medical infrastructure have broken down.
An outbreak that began in Peru in 1991 and moved through South America, caused more than 1.1 million cases until 1994, including more than 10,500 deaths, according to World Health Organization (WHO) figures.
There are an estimated three to five million cholera cases every year, with about 100,000 to 120,000 deaths.