Cholera has already claimed more than 3,600 lives in Haiti, but the outbreak still hasn't reached its peak, the World Health Organization said Tuesday.

WHO spokeswoman Fadela Chaib told reporters in Geneva that the illness has infected at least 171,000 but the death rate still hasn't fallen enough.

She said the illness currently has a 2.2-per cent mortality rate. That's way down from the nine per cent from late last year. But the rate still needs to drop to less than one per cent in order for officials to declare the peak of the outbreak reached. Officials don't expect that to happen for a few more weeks at least, she said.

"There will be certainly many more cases of cholera in Haiti, it's certain. But what is sure is that fewer people will die," she said.

Matthias Schmale, an International Federation of the Red Cross undersecretary-general, told reporters Tuesday that officials worry the disease is still spreading. He ntoed "if we had the magic solution, we would be doing it."

The cholera epidemic began in October 2010, fuelled by poor sanitation and poor access to clean water and hand soap. The outbreak spread to every section of the country by December.

Chaib said that some rural areas that are difficult to access now record more than 100 new cases a day. The disease has also spread to the neighboring Dominican Republic, and isolated cases have been found in the United States.

Some in Haiti have blamed the outbreak on United Nations peacekeepers from Nepal, because the first cases were found near their base in Haiti. While the UN has rejected any idea the base was involved, saying its sanitation was airtight, it has appointed an independent panel to investigate the source of the outbreak.

With reports from the Associated Press