Confirmed cases of Ebola in Congo have reached 1,003, according to health officials in the Congo. 

Of those cases, nearly one-fourth have died from the disease in the latest outbreak, ABC News reported. Since the outbreak was declared on May 15, at least 365 patients are in hospitals or isolation, Congo’s Ministry of Health said on Sunday. 

The outbreak is caused by the rare Bundibugyo virus. The strain has no vaccines or treatment. Contact tracing and identifying patient zero has been impeded by ongoing violence in the region. 

Officials say there are likely many more cases that haven't been confirmed, and the outbreak hasn't likely reached its peak.