Cholera is an acute diarrhoeal disease that can kill within hours if left untreated.
There are an estimated 3–5 million cholera cases and 100 000–120 000 deaths due to cholera every year.
Up to 80% of cases can be successfully treated with oral rehydration salts.
Provision of safe water and sanitation is critical in reducing the impact of cholera and other waterborne diseases.
Source: World Health Organisation
Bill Clinton, the UN's special envoy to Haiti, said on Wednesday that a member of the global organisation's peacekeeping force was probably responsible for bringing cholera to the Caribbean country, but may not have known that he was doing so.
Clinton was asked after a hospital tour if he agreed with a statement by Susan Rice, the US Ambassador to the UN, about holding accountable those who brought cholera to Haiti.
Studies have suggested that peacekeepers from Nepal probably introduced the disease to Haiti for the first time, months after the January 2010 earthquake.
"First of all, the United Nations has spent a great deal of money in Haiti," Clinton told reporters. "Secondly, I don't know that the person who introduced cholera in Haiti, the UN peacekeeper, or soldier from South Asia, was aware that he was carrying the virus."
Clinton added: "It was the proximate cause of cholera. That is, he was carrying the cholera strain. It came from his waste stream into the waterways of Haiti, into the bodies of Haitians."
But Clinton added that what "really caused" the cholera outbreak was the country's lack of proper sanitation.
"Unless we know that he knew or that they knew, the people that sent him, that he was carrying that virus and therefore that he could cause the amount of death and misery and sickness, I think it's better to focus on fixing it," Clinton said.
The former US presidentmade the remarks after he toured a new hospital in the Central Plateau region.
'Confluence of factors'
The UN responded to Clinton's comments by saying: "The Secretary-General set up a panel of experts regarding the cholera outbreak. Their conclusion was that it was not possible to be conclusive about how cholera was introduced into Haiti, that the cholera outbreak was caused by a confluence of factors, and was not the fault of, or deliberate action of a group or individual.”
Brian Concannon, director of the Institute for Justice and Democracy in Haiti and one of the lawyers who has filed claims against the UN on behalf of cholera victims, put the blame on the UN.
Concannon told Al Jazeera: "The proximate cause of the epidemic are the UN and they are to blame."
The cholera outbreak prompted a Haitian law firm and its international partner to file a complaint against the UN last year on behalf of the victims, which is under review by the world body's legal office.
Cholera has killed more than 7,000 people and made more than 526,000 others sick since it was introduced to Haiti in 2010, according to Haitian health officials.