The outbreak of the deadly Bundibugyo species of Ebola in the eastern Democratic Republic of the Congo (DRC) is expanding, while the push to accelerate testing and identify effective treatment options continues, the UN World Health Organisation (WHO) said on Tuesday.

The outbreak’s “true scale has not yet been fully established,” said Dr. Anne Ancia, WHO’s representative to the DRC.

Speaking from Bunia, the capital of Ituri province at the heart of the outbreak, Dr. Ancia told reporters in Geneva that as of 4 July, the country’s Government has recorded 1,561 confirmed cases, including 506 deaths and 254 people recovered. More than 10,000 contacts are being monitored.

In support of the government-led response, WHO is strengthening its understanding of the history of every case of infection “so that we can really understand the chain of transmission” and isolate every contact case, Dr. Ancia said, according to UN News Centre.

Encouraging developments include the progress made on testing, as daily capacity has increased from 30 tests in Kinshasa to more than 2,000, “thanks to 10 decentralised laboratories established in the affected provinces”, the WHO representative explained, with the most recent lab opening in Bunia.