The cases have occurred in the Tchomia health zone within the Ituri district, said Eustace Kyroussis, head of the World Health Organisation office in the area.
Progress was being made in controlling the outbreak, he said.
Numerous cases have been detected on the small island of Rukwanzi in Lake Albert, recently inhabited by fishermen and their families, said local official Dieudonne Rwabona.
"On Rukwanzi, an island of three square kilometres (1.2 square miles), there is no health centre nor latrine," Rwabona said.
Congolese police have begun evacuating the families from the island and sending them back to their villages of origin.
The cholera outbreak in the region has essentially been due to a lack of drinkable water, forcing residents to consume non-treated water from Lake Albert.
Cholera is an acute intestinal infection that can be fatal if untreated.