The waterborne disease has killed more than 130 people and sickened close to 5,000 others in the southern African country since March. Luke Arend, head of the Lusaka office of aid group Medecins Sans Frontiers, says that's the highest number of cases in a decade.
Health ministry spokesman Dr. Reuben Mbewe said Thursday the outbreak was due to flooding in Lusaka, the capital, after torrential rains. Shallow wells that are a main source of domestic water have become contaminated by overflow from pit latrines.
The government and aid group have set up special treatment centers. The government has banned gatherings such as weddings and wakes to try to control the spread.