At least eight people have died from the waterborne illness in the city of around 1 million, and 104 are receiving medical care at a treatment centre set up by MSF's Belgian chapter.

"We are seeing that the worst hit people are those who live in the poorest neighbourhoods. That is where the people have no access to drinking water and the hygiene conditions are poor," said Bertrand Perrochet, MSF's emergency pool coordinator.

Cholera spreads mostly during the rainy season due to floods contaminating water systems. At its most acute, the disease causes sudden diarrhoea that can lead to death by severe dehydration and kidney failure.

It is endemic in many parts of Congo, which is still recovering from a 1998-2003 war that killed an estimated 4 million people, mainly through hunger and disease, and left infrastructure in ruins.

Health officials have recorded 150 new cases, including five deaths, in the town of Bukama, about 300 km (192 miles) north of Lubumbashi since January 1. Another cholera outbreak has been reported in Likasi, 90 km (58 miles) northwest of Lubumbashi.

However, large-scale epidemics in Lubumbashi, the heavily populated capital of Katanga, are relatively rare.

"The last major epidemic (in Lubumbashi) was in 2003. In Katanga, there are of course outbreaks every year, but this year it started very early during the dry season," Perrochet said.

MSF reinforced local health workers last week, sending a team of 15 doctors, nurses, sanitation experts, and logisticians to Lubumbashi. It plans to send a team to Likasi next week.