The death toll from the ongoing Ebola outbreak in the Democratic Republic of the Congo has surpassed 500, the country’s Information Ministry said Monday.

The ministry reported 1,561 confirmed cases, including 506 deaths. It said 628 patients are currently receiving treatment in hospitals and isolation centres, while 253 people have recovered.

The Africa Centres for Disease Control and Prevention (Africa CDC) expressed concern that patients testing positive for the disease are repeatedly fleeing isolation centres, complicating containment efforts.

In neighboring Uganda, 19 infections have been recorded, including two deaths, since the outbreak was first identified in May. The Ugandan cases are linked to the outbreak in north-eastern Congo.

Ebola is transmitted through direct contact with infected bodily fluids.

The current outbreak involves the Bundibugyo variant, which has proved difficult to contain due to the absence of a licensed vaccine or specific antiviral treatment.

However, two antiviral therapies have recently entered clinical testing and have been undergoing evaluation since last week.