The number of Haitians infected by cholera has risen more than 300 percent in the past year as early rains, poor sanitation, and a lack of funding means the impoverished Caribbean nation struggles to stem the disease, the United Nations said.
From January to April this year, 14,226 Haitians were infected with cholera, a 306 percent increase from the same period last year, with the Haitian capital Port-au-Prince hardest hit.
"An upsurge in the last quarter of 2014 continues to affect Port-au-Prince's metropolitan area, illustrating the shift of the epidemic from rural to urban areas," said the latest U.N. humanitarian agency (OCHA) report on Haiti. "This raises concerns with regards to the upcoming rainy season, when cholera in Haiti traditionally expands."
Cholera, a water-borne disease, has killed nearly 9,000 Haitians and infected 738,000 since the outbreak began in the aftermath of a devastating 2010 earthquake.
Infection is caused by drinking and using contaminated water, triggering diarrhea and vomiting that often brings on severe dehydration, which if not treated quickly can be fatal.
Haiti leads the world in suspected cholera cases. So far this year, at least 121 Haitians have died from cholera, according to OCHA.
The rainy season - which tends to cause a spike in water-borne bacterial diseases like cholera - usually runs from April to June, but this year heavy rains began to fall a month early.
Evidence strongly suggests U.N. peacekeepers from Nepal were the source of Haiti's cholera epidemic, when they were stationed near a river and discharged raw sewage, according to a 2011 report from the U.S. Centers for Disease Control and Prevention.
The U.N. was sued in 2013 by the Boston-based rights group, the Institute for Justice and Democracy in Haiti, demanding improved water and sanitation infrastructure, compensation for thousands of cholera victims and an apology.
A New York federal judge threw out the lawsuit in January, saying the U.N. could not be sued because it has legal immunity.
The rights group recently filed an appeal.
A lack of funding amid numerous global crises has meant little progress has been made on improving sanitation in Haiti, a key way of combatting cholera.
Forty percent of Haiti's population of 10 million do not have access to clean water, while nearly half of the country's hospitals lack either drinking water or sanitation, according to the Pan American Health Organization.
In a bid to eradicate cholera in Haiti and the neighboring Dominican Republic, the U.N. launched a $2.1 billion 10-year campaign in late 2012, of which just 18 percent has been funded.