An outbreak of cholera has killed 23 people in eastern Democratic Republic of Congo over the past three weeks and infected more than 850 others, local authorities said on Tuesday.

Badly built latrines had caused water supplies to become contaminated and triggered the outbreaks, which were centred around the towns of Fizi, Nundu and Uvira on the shores of Lake Tanganyika, a medical official in South Kivu province said.

“At least 23 people have died from a total of 855 cases during the last three weeks in the province,” Dr Ghislain Bisimwa, South Kivu’s medical officer, told Reuters.

“The number of cases is worrying but we often get epidemics like this because there is a lack of safe drinking water and people’s living conditions are not very good,” he added.

Africa had been free of cholera, a disease that can quickly cause severe dehydration and death, for more than a century when it hit western regions in 1970. It spread fast and eventually became endemic across much of the continent.

Years of fighting have left eastern Congo out of the reach of many aid agencies even though the country’s five-year war was declared over in 2003.

More than 1,000 Congolese civilians still die every day due to the festering conflict, mainly from disease and malnutrition, according to the International Rescue Committee.

The World Health Organisation (WHO) said in November that cholera had killed 1,663 people in Africa in the first 10 months of 2003, with over 70,000 cases reported.