Congo's Ebola outbreak has spread to a new health zone in the northeastern province of Ituri, authorities said on Wednesday, as fresh infections underline sustained transmission more than three weeks after the epidemic was declared. 

The health ministry said Tchomia, about 50 kilometres south of the provincial capital Bunia on the shores of Lake Albert, has become the latest affected health zone, bringing the total number of affected zones to 26 nationwide and 18 in Ituri province, which accounts for more than 94% of confirmed cases.

A health zone in Congo’s healthcare system covers a defined area with a network of clinics and a referral hospital.

The government's latest situation report said 37 new confirmed cases, including 12 deaths, were reported in the previous 24 hours, all in Ituri.

The outbreak has so far recorded 635 confirmed cases and 127 deaths across three eastern provinces.

The epidemic, caused by the rare Bundibugyo strain of the virus, for which there is no approved vaccine or specific treatment, was declared on May 15. It has since spread across Ituri, North Kivu and South Kivu, regions marked by insecurity, displacement and cross-border movement.

Eight patients were newly declared recovered, bringing the total number of recoveries to 30, while treatment activities have been launched at Ebola centres in Bunia and Rwampara, the report said.