When the 2026 Ebola outbreak caused by Bundibugyo virus (BDBV) began, few diagnostic tests had been validated for this rare species of ebolavirus. An international network of nine laboratories evaluated four candidate PCR tests from two manufacturers in just two weeks, according to a study in The Lancet Infectious Diseases presented on September 8, 2026, by the German Center for Infection Research (DZIF).
A rare virus, a fast-moving outbreak
Bundibugyo virus is one of the ebolaviruses that cause Ebola disease in humans, but outbreaks have been rare, with historical case fatality rates of roughly 30 to 50%. The 2026 outbreak affected the Democratic Republic of the Congo and Uganda, and the World Health Organization declared it a Public Health Emergency of International Concern on May 17, 2026. Because most Ebola diagnostics were designed for Zaire ebolavirus, laboratories needed evidence that tests could reliably detect BDBV.
Building a reference standard
The diagnostic study was led by Professor Christian Drosten at Charité – Universitätsmedizin Berlin. His team isolated BDBV genetic material from a throat swab of a patient from the United States who was admitted to Charité on May 20, 2026, after infection in the DRC. This material was used to produce a reference standard against which all candidate tests could be compared.
Two weeks, nine laboratories
The network included DZIF laboratories, members of the German National University Medicine Network (NUM), several European research consortia, major university hospitals, and biosafety level 4 facilities. Working in parallel, the laboratories completed the analytical and clinical performance assessment of all four PCR assays within two weeks. No cross-reactivity was found.
Drosten pointed to a gap in the system: “Public funding could help accelerate the regulatory evaluation of diagnostic tests for rare, high-consequence pathogens, where commercial incentives are limited.”
Vaccine findings
A companion study in the same journal, led by Professor Stefan Pöhlmann at the German Primate Center in Göttingen, looked at the virus itself. Using pseudoviruses carrying the surface glycoproteins of BDBV strains from 2007–08, 2012, and 2026, the team found no evidence that the 2026 virus enters human cells more efficiently than earlier variants.
The researchers also tested blood from 10 healthy volunteers who had received the licensed VSV-ZEBOV Ebola vaccine. Antibodies taken at day 28 and day 180 neutralized pseudoviruses with the glycoproteins of all three BDBV strains, including the 2026 strain. BDBV-specific neutralization was found in 6 of the 10 volunteers at both time points, although neutralizing activity was 3.5 to 3.6 times lower than against Ebola virus. The authors say this suggests the vaccine may offer some cross-protection, but the results need to be confirmed with authentic BDBV.
Preparing before the next outbreak
Both groups conclude that international laboratory networks, reference materials, and regulatory pathways should be in place before an outbreak starts. Research-use PCR assays for BDBV were available within days, but independent evaluation is what turns a new assay into a test that laboratories and health authorities can rely on.