A cholera epidemic in Haiti has killed almost 8,000 people leading the United Nations to launch a $2 billion appeal for help in stopping the deaths.

The campaign comes as reports begin to surface that the current outbreak, the worst in the world at this time, started in a United Nations camp. Dr. Daniele Lantagne, a cholera specialist, said that UN troops from Nepal arrived with the disease. Nepal has widespread cholera cases and the molecular structure of the Haitian cholera matches strains from Nepal in 2010.

The news puts the UN at risk of claims from the families of those who died in the current outbreak. Prior to the current outbreak, even with the catastrophic earthquake and multiple hurricanes, the nation had not had one case of cholera in over 100 years.

Cholera is spread through human waste. Once it enters a water supply, such as ones in Haiti without effective sewage disposal systems, it’s extremely difficult to stop.

Despite the report that says toilets in the UN camp allowed infected waste to enter the Meye River, the UN report and UN officials claim the outbreak was “not the fault of any group or individual.”

Victims’ families have lodged an official claim at UN headquarters in New York City asking for billions of dollars in damages.