The cholera outbreak that has killed nearly 5,000 people in Haiti was caused by a South Asian strain that contaminated a river where tens of thousands of people wash, bath, drink and play, a U.N. independent panel of experts said Wednesday.

Although many have blamed the epidemic on U.N. peacekeepers from South Asia working in Haiti, the report issued by the panel declined to point the finger at any single group for the outbreak, saying it was the result of a "confluence of circumstances."

"The evidence overwhelmingly supports the conclusion that the source of the Haiti cholera outbreak was due to contamination of the Meye Tributary of the Artibonite River with a pathogenic strain of current South Asian type Vibrio cholerae as a result of human activity," the report said.

It said the panel concluded the epidemic "was not the fault of, or deliberate action of, a group or individual."

U.N. Secretary-General Ban Ki-moon requested the independent probe amid reports of poor sanitation at a U.N. base housing Nepalese peacekeepers near Mirebalais, the central town where the outbreak was first reported.

Besides killing almost 5,000 people in a country still recovering from a devastating earthquake more than a year ago, the outbreak has sickened another 250,000.

The belief that the Nepalese peacekeepers are to blame for the epidemic is widespread in Haiti, straining relations between the population and U.N. personnel. Angry protests berating the peacekeepers erupted late last year, and just last week about 100 demonstrators blamed the United Nations for the spread of cholera.

Ban will carefully consider the panel's findings and recommendations, U.N. spokesman Martin Nesirky said.

The spokesman said the U.N. chief will convene a task force to study the findings and recommendations to ensure they are dealt with promptly.

Haitian officials in the health ministry declined to comment Wednesday afternoon, saying they had not yet read the report. The U.N. envoy to Haiti Edmond Mulet was to deliver the report to the government Wednesday.

Doctors Without Borders, a medical charity that has treated about 130,000 cholera patients since the outbreak, welcomed the report's release.

"We're happy that there's a process to ensure the origins of the epidemic can be investigated, and that the report has been made public for full transparency," said Sylvain Groulx, the group's chief of mission in Haiti.

The report came amid concerns from the U.S.-based medical aid group Partners in Health that an increase in new cholera patients in rural Haiti may signal a new surge of the epidemic with the onset of the spring rainy season.

Panel members said Haiti's outbreak underscored the need for U.N. personnel and other first responders coming from countries where cholera is endemic to be screened for the disease, receive a prophylactic dose of appropriate antibiotics before departure, or both.

They also recommended that U.N. installations worldwide treat fecal waste using on-site systems "that inactivate pathogens before disposal."

In their report's conclusions, panel members said the Artibonite River's canal system and delta "provide optimal conditions for rapid proliferation" of cholera, that Haitians lacked immunity to the disease, and that many areas of the country suffer from poor water and sanitation conditions.

It also said the South Asia strain that caused the outbreak "causes a more severe diarrhea due to an increase in the production of a classical type of cholera toxin and has the propensity of protracting outbreaks of cholera."

"The conditions in which cholera patients were initially treated in medical facilities did not help in the prevention of the spread of the disease to other patients or to the health workers," it added.

"The introduction of this cholera strain as a result of environmental contamination with feces could not have been the source of such an outbreak without simultaneous water and sanitation and health care system deficiencies," panel members said.


Associated Press reporter Trenton Daniel in Port-au-Prince contributed to this report.