Marburg outbreak is reported in Uganda, threatening to complicate Ebola response in region

Health Marburg outbreak is reported in Uganda, threatening to complicate Ebola response in region The outbreak is said to be localized Manage alerts for this article Email this article Share this article By Helen BranswellJune 30, 2026 Infectious Diseases Correspondent Helen BranswellHelen Branswell covers issues broadly related to infectious diseases, including outbreaks, preparedness, research, and vaccine development. Follow her on Mastodon and Bluesky. You can reach Helen on Signal at hbranswell.01. Uganda formally reported to the World Health Organization on Tuesday that it had detected a Marburg disease outbreak in the western part of the country, a spokesperson for the Geneva-based global health agency told STAT. The development could further complicate the effort to contain what is already the third-largest Ebola outbreak on record in Central Africa. Both diseases are viral hemorrhagic fevers. The Ugandan government has not yet publicly disclosed a Marburg outbreak. But the U.S. embassy in the Ugandan capital, Kampala, issued a health alert on Monday, saying it had been made aware of a possible case of Marburg in the country. The alert was a level 4 advisory alerting Americans they should not travel to Uganda.Advertisement The notification from Uganda to the WHO was of a single case. But a well-placed source — who answered questions from STAT on the proviso that their name and place of work would not be identified — said that Uganda had actually detected two cases of Marburg as of Monday. The individual said it appeared that at this point, the outbreak is localized. The source said the WHO’s outreach to other countries to inform them of the information it was receiving about the outbreak also cited two confirmed cases. That notice went out through a password-secure disease news-sharing network run through the International Health Regulations, a treaty to which most countries — including the United States — are signatories. “We continue to request further information, and once this is received from Ugandan health authorities, we will continue to update Member States, and the wider public,” the WHO said in a statement given to STAT.Advertisement STAT has reached out to Uganda’s health ministry for comment but has not yet received a reply. Nahid Bhadelia, director of Boston University’s Center on Emerging Infectious Diseases, suggested the U.S. embassy’s alert may have been an attempt to force the country to publicly acknowledge something that has been likely known for some days. “The embassy releasing this does make me feel like this is something that is a bit more confirmed,” she said. Marburg is caused by a filovirus, the broad family to which Ebolaviruses belong. The viruses trigger the same type of disease and are spread via the same methods — contact with the bodily fluids of an infected person, or the preparation of an infected corpse for traditional burials. Of the 20 or so recorded Marburg outbreaks to have been confirmed since the virus was identified in 1967, five occurred in Uganda, two were in tourists who were infected there but confirmed after returning home, and one involved lab workers infected by monkeys from Uganda. There are currently no licensed vaccines to prevent Marburg infection, though several candidates are at various stages of being tested. And Marburg vaccine work is further advanced than efforts to test vaccines against Bundibugyo, the species of Ebola responsible for the ongoing outbreak in the Democratic Republic of the Congo, that outbreak’s epicenter. Several are in development, but the entities working on these vaccines don’t currently have doses available to mount a clinical trial. Trials of these vaccines are months down the road. Uganda is known to be highly effective in containing outbreaks of Ebola and Marburg. But it is likewise known to be hesitant to disclose much information during such outbreaks, possibly driven by the importance tourism plays in its economy. The detection of a Marburg outbreak in Uganda comes at a time when the government there is trying to get countries — including the United States — to roll back entry restrictions on Ugandan nationals or travelers who have been in Uganda within the previous 21 days, the incubation period for Ebola and Marburg.Advertisement “There is a need to review these restrictions,” Uganda’s health minister, Chris Baryomunsi, said at a recent press conference, an account of which was reported on the country’s NBS Television. He argued that with good public health measures, including stringent airport screening, the risk of exporting Ebola from Uganda is very low. He did not refer to the Marburg outbreak. Baryomunsi also made the argument that Uganda’s Bundibugyo outbreak was under control. The country has recorded 20 Ebola cases in the current outbreak, 15 of which were Congolese nationals who had traveled to Uganda; some of the other cases were Ugandan health workers infected by those travelers. The country hasn’t detected a new case of Ebola in over two weeks. This story has been updated with a statement from the WHO. Correction: An earlier version of this story incorrectly identified Ugandan Health Minister Chris Baryomunsi. infectious diseases, public health, Vaccines Submit a correction requestReprints Helen Branswell Infectious Diseases Correspondent Helen Branswell covers issues broadly related to infectious diseases, including outbreaks, preparedness, research, and vaccine development. Follow her on Mastodon and Bluesky. You can reach Helen on Signal at hbranswell.01. 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