The spread of the cholera outbreak in Haiti is beginning to slow down, even as humanitarian agencies continue to step up treatment and preventive measures, with the number of cases having risen to more than 3,000, including 254 deaths, the United Nations reported on Monday.

Efforts to contain the spread of the disease are the top priority for humanitarian agencies, which are trying to prevent the epidemic from reaching camps housing up to a million internally displaced persons (IDPs) left homeless by the massive earthquake in January, which devastated the capital Port-au-Prince and several other cities.

"The consequences of the epidemic reaching the cities – a very real prospect – would be devastating to all, including those still living in camps after the earthquake," the UN Office for the Coordination of Humanitarian Affairs (OCHA) cautioned.

The UN World Health Organization (WHO) and Haiti's health ministry have confirmed five cholera cases in Port-au-Prince, but the patients were people who got infected while visiting Artibonite department and then travelling to the capital.

"This is an extremely serious situation and based on experience with epidemics elsewhere it would be irresponsible to plan for anything but a considerably wider outbreak," said Nigel Fisher, UN Humanitarian Coordinator in Haiti. "We are particularly concerned about Port-au-Prince and those in the slum areas as well as in the camps, but we are also preparing for outbreaks in the rest of the country."

The UN Stabilization Mission in Haiti (MINUSTAH) is helping the National Directorate of Water Supply and Sanitation (DINEPA) to distribute more than 800 kilograms of chlorine powder to piped water distribution points in some of the worst affected areas along the Artibonite river, according to OCHA.

Humanitarian agencies in the water and sanitation cluster are working to ensure that people have access to clean water, assessing hygiene conditions at water points, distributing soap and carrying out an awareness campaign in affected and at-risk areas.

They have particularly targeted the 17 communal sections along the Artibonite river, which is believed to be the source of the epidemic, for distributions of water purification tablets, soap and oral rehydration salts.

"While we have sufficient supplies to handle this crisis at present, we must look at ensuring additional personnel and bringing in more supplies and support so we are ready to cope if this outbreak spreads further," said Mr. Fisher.

The UN World Food Programme (WFP) has commenced the distribution of ready-to-eat meals as well as high energy biscuits to hospitals in affected areas, in en effort to ensure people do not eat food that could have been cooked with contaminated water.

Outstanding needs in the efforts to contain the spread of the disease include additional medical personnel in Artibonite, support for the public information campaign on prevention and response, and facilities in which patients with confirmed symptoms can be isolated as they receive treatment.

Cholera is an acute intestinal infection caused by eating food or drinking contaminated with the bacterium known vibrio cholerae. Symptoms include watery diarrhoea which can quickly lead to severe dehydration and death if not quickly treated. Vomiting also occurs in most patients.