Health authorities in the Democratic Republic of the Congo (DRC) are tracking a growing share of people exposed to Ebola, but the epidemic in the country's restive east continues to outpace their ability to find and isolate the sick, the World Health Organization (WHO) has warned.

More than 2,000 people have died from Ebola in the Congo. However, only 30 per cent of confirmed cases are seeking help.

Explainer: Why DR Congo's Ebola outbreak is spreading faster -- and deadlier-