The UN Office for the Coordination of Humanitarian Affairs (OCHA) said that a total of 1,500 cholera cases has been reported in South Sudan till date, media reported Tuesday.
"The outbreak is spreading to Yei and Kajo Keji in Central Equatoria State," Xinhua quoted UN spokesman Stephane Dujarric as saying Monday.
According to reports, out of the 1,500 positive cases, 31 have died.
Since the outbreak of cholera in the capital Juba in May, the reported cholera cases has doubled almost every day, the UN Children's Fund (UNICEF) said.
Since January, UNICEF has warned of the threat of cholera, due to the desperate overcrowding of camps following continued violence, and also the rainy season.
Last month, UNICEF said that unless nutrition treatment is scaled up immediately, up to 50,000 children under the age of five are likely to die.