The rise was particularly strong in the capital, Port-au-Prince, and the southern peninsula. In Port-au-Prince alone, WHO reported 18,182 new cases between May 2 and June 12.

A shortage of funds was also threatening international health efforts in Haiti, it said.

WHO said the number of nongovernmental organizations (NGOs) fighting cholera in the country had fallen from several hundred at the beginning of the outbreak last year to about 60 because of insufficient funding.

For the same reason, the remaining NGOs had cut their programs providing clean water and sanitation and other measures to contain the epidemic.

According to Haiti's Ministry of Public Health, as of June 12, 2011, there were a total of 344,623 cases of cholera and 5,397 related deaths.