“With a disease like cholera, the first hours are the most important to save lives and make a significant difference. With a surveillance and alarm system that does not give exact data, more lives are in danger,” Oliver Schulz said.

Doctors Without Borders and Partners in Health, a Boston-based medical aid group working in Haiti’s Central Plateau, said while the number of people contracting cholera is down from the onset of the disease, too many Haitians continue to get sick — and die — from it. They agree with Piarroux that the low incidences of the disease in the dry season provides the opportunity to eradicate it.

“There is a sense that it’s OK for people to be getting sick from a preventable disease,” said Dr. Louise Ivers of Partners in Health, which saw a spike in January and February. “No deaths from cholera should be acceptable. We should be striving for zero deaths.”

Both Ivers and Schulz say they welcome the 10-year cholera elimination initiative, and Haiti’s National Cholera Plan, which the Health Ministry launched in February as part of the initiative. But while the plan details the government’s roadmap for eradicating the disease, concerns about funding remain unclear.

“We do not know how the $2.2 billion will be raised and how patients will be treated in the coming weeks, in case numbers rise again,” Schulz said.

Christophe Boulierac, a spokesman with UNICEF in Haiti, said the U.N. has discussed funding with the government and is awaiting approval of how the money should be disbursed.

In lending his support to eliminating cholera, Ban announced that the U.N. was chipping in $23.5 million — about 1 percent of the plan’s $2.27 billion price tag — for 2013.

Johnston, who blames the global body’s peacekeepers for introducing cholera to Haiti, said it “has the moral, if not the legal responsibility to fund the cholera eradication plan itself.”

His criticism of the U.N. joins that of Boston-based Physicians for Haiti, which on Friday accused the U.N. of not doing enough to stop the spread of the disease.

Two years after an independent panel of experts issued a report on Haiti’s cholera outbreak, the U.N. has failed to implement many of its own recommendations, the group said. The report, commissioned by Ban, steered clear of placing blame for the outbreak but listed seven recommendations to move forward.

A spokesman for the U.N. secretary general said five of the seven recommendations are being implemented. For example, additional wastewater treatment centers have been installed along with septic tanks and other sanitary measures at all U.N. camps in Haiti.

Meanwhile, as the rains begin, Piarroux said it’s important for Haiti to view eliminating cholera “as an emergency” issue.

“We can stop cholera transmission before providing safe water to the entire population,’’ he said. “Of course, the end of cholera will not be a reason to stop investments in water supply.”