Cholera quietly still kills dozens a month in Haiti

The persistence of the preventable disease has alarmed public health experts who fear that attention and resources have been diverted by newer challenges, including the regional spread of the Zika virus and the political crisis that recently halted Haiti's elections.

"Once it is established in a country's aquatic reservoir it is extremely difficult to eradicate," said Afsar Ali, a researcher at the University of Florida who has led studies of cholera in Haiti for years.

Dr. Joseph Donald Francois, who coordinates the health ministry's efforts to combat the illness, still believes Haiti, with international help, can eliminate cholera by 2022.

In the first year of the outbreak, more than 200 international organizations were providing money and expertise to combat the illness in Haiti.

Researchers say there is ample evidence the disease was introduced to the country's biggest river by inadequately treated sewage from a base of U.N. peacekeepers from Nepal, one of the units that have rotated in and out of a multinational force in Haiti since 2004.

While the number of cholera cases has been significantly reduced from its first wave and the mortality rate has been slashed to lower than 1 percent from a high of 9 percent in December 2010, the fact that cholera is still killing Haitians more than five years on is galling to public health experts.