A cholera outbreak in Sudan has spread to the western Darfur region, posing a serious threat to the 2.5 million living in refugee camps in dilapidated conditions.

A U.N. statement sent late on Sunday says, "The World Health Organization (WHO) in Nyala (south Darfur) confirmed 65 cases of acute watery diarrhea," reports Reuters news.

Cholera is an acute, diarrhea illness caused by infection of the intestine with the bacterium Vibrio cholerae.

An aid agency confirmed one cholera fatality in Gereida, in southeast Darfur, where almost 100,000 people have fled their homes to seek safety in the town.