WHO Clears First Molecular Test for Rare Ebola Strain: What It Means for Outbreak

On July 2, 2026, the World Health Organization (WHO) added the first molecular diagnostic test for the Bundibugyo virus (BDBV) to its Emergency Use Listing (EUL). The test, which detects the virus's genetic material in blood samples, is intended to enable rapid and accurate confirmation of infections during the ongoing outbreak in Africa.

The announcement comes less than two months after the WHO declared a Public Health Emergency of International Concern (PHEIC) on May 17, 2026, following an outbreak of the Bundibugyo strain of the Ebola virus in the Democratic Republic of Congo (DRC) and neighbouring Uganda. As of July 1, the DRC had reported 1,460 confirmed cases, including 452 deaths, while Uganda had 20 confirmed cases, two deaths, and one probable death. At least 229 patients have recovered — 213 in the DRC and 16 in Uganda.

Bundibugyo virus disease (BVD) is a rare form of Ebola, with only two previous outbreaks. It presents challenges in diagnosis because its symptoms resemble other febrile illnesses such as malaria. Laboratory confirmation using PCR or antibody-based assays is essential for accurate diagnosis. Currently, there are no approved vaccines or specific treatments for BVD, making rapid case identification, isolation, contact tracing, and safe burials the primary control measures.

The WHO's EUL listing is a risk-based procedure that assesses the quality, safety, and performance of essential health products during public health emergencies. It expedites the availability of unlicensed vaccines, therapeutics, and diagnostics to affected populations. This process was previously used for COVID-19 vaccines and diagnostics.

Yukiko Nakatani, WHO Assistant Director-General for Health Systems, Access and Data, stated: 'During a fast-moving outbreak, timely access to quality-assured diagnostic tests can make a critical difference in containing transmission. Through this Emergency Use Listing, WHO is helping countries access trusted diagnostic tools more rapidly so that they can respond more effectively.'

The WHO, along with the Africa Centres for Disease Control and Prevention, has expanded laboratory testing capacity to 10 laboratories across affected provinces, with a reported capacity of over 2,000 tests per day. Additional applications for Bundibugyo virus diagnostics are under review.

The listing of a quality-assured molecular test is expected to speed up case confirmation, improve surveillance, and help interrupt transmission, ultimately aiding in controlling the deadliest Bundibugyo outbreak on record.