UNITED NATIONS, United States (CMC) — Outgoing United Nations Secretary General Ban Ki-moon Tuesday publicly expressed regret for the outbreak of cholera in Haiti.

Addressing the United Nations General Assembly (UNGA) for the last time, Ban said the cholera outbreak and the sexual abuse by UN peacekeepers in Central African had “tarnished the reputation of the United Nations and, far worse, traumatized many people we serve”.

Ban, who steps down at the end of this year after serving two five-year terms, said he felt “tremendous regret and sorrow at the profound suffering of Haitians affected by cholera.

 “Let us work together to meet our obligations to the Haitian people,” he said, adding the UN has a “moral responsibility” to do so.

The country was free of cholera until 2010, when UN peacekeepers dumped infected sewage into a river.

A 2011 study by the US Centre for Disease Control and Prevention said UN peacekeepers from Nepal, where cholera is endemic, were the likely cause of the outbreak.

Since then, more than 9,000 people have died of the disease that causes uncontrollable diarrhoea and 800,000 people have fallen ill, mostly in the first two years of the outbreak.

The UN has not legally accepted responsibility for the outbreak. An independent panel appointed by Ban issued a report in 2011 that did not determine conclusively how the cholera was introduced to Haiti.

In June last year, lawyers representing a number of Haitian cholera victims filed an appeal against a ruling by a US judge that the UN is legally immune from prosecution.

The Haitians had taken the UN to court accusing it of being responsible for the outbreak of the cholera epidemic.

But Federal Judge J Paul ruled last year that the UN was legally immune from prosecution for importing cholera into Haiti.

In their 62 page appeal, the lawyers from the Boston-based Institute for Justice and Democracy in Haiti (IJDH), the San Francisco-based Centre for Law and Global Justice, and the Miami-based firm of famed immigration lawyer argued that the judge had erred in ruling that the UN and its military force, the UN Mission to Stabilize Haiti (MINUSTAH), were immune “despite having violated their treaty obligation to provide a mode to settle private law claims”.

Cholera is a water-borne bacteria, which principally spreads via sewage. In October 2010, cholera-infected Nepalese MINUSTAH soldiers allowed faeces from their out-houses to flow into the headwaters of Haiti’s largest river, the Artibonite, used for drinking, washing, and irrigation.