A new Ebola case was confirmed in the Eastern Democratic Republic of the Congo in an area where authorities believed that the epidemic had been controlled after 23 days without any new infections.
In an update announced on Friday, the health ministry said that the new case had been discovered in the Beni conflict region.
"The patient appears to have been infected after being exposed to physical fluids by a patient who had recovered from Ebola. A detailed investigation is underway along with a virus sequence to determine the connection epidemiological, "he said.
The announcement came only three days after the ministry reported "big progress", saying that the epidemic appeared under control in the Beni area.
Over 500 people have died since the death influenza virus ended last August in the Kivu North region bordering Uganda and Rwanda.
Beni had been particularly difficult, accounting for 118 deaths.
Despite the increase, the ministry had warned that Beni was in danger of the surrounding areas of Katwa and Butembo, where new case scores have come to light this month.
Over the last 21 days, there were 58 cases confirmed in Katwa and 16 in Butembo, the ministry said.
So far, 536 people have died as a result of the Ebola epidemic, which began on August 1.
Under a program that started a week later, 82,583 people have been vaccinated against the disease, almost two-thirds are Beni, Katwa and Butembo.
A new epidemic can only be reported when the country has not recorded any new case of Ebola for 42 days in a row.
International health experts have been helping in the eastern DR Congo but attempts to include the disease have been hampered by violence in the region, where militia groups are too low.