On Jan. 13, 2025, the World Health Organization (WHO) informed its Member States and IHR State Parties of an outbreak of suspected Marburg Virus Disease (MVD) in the Kagera region of the United Republic of Tanzania using our secure web-based platform—the Event Information Site (EIS). Under the International Health Regulations, the EIS is used to issue rapid alerts to Member States of acute and rapidly developing public health risks and events with possible international implications.

On 10 January 2025, WHO received reliable reports from in-country sources regarding suspected cases of MVD in the Kagera region of the United Republic of Tanzania. Six people were reported to have been affected, five of whom had died. The cases presented with similar symptoms of headache, high fever, back pain, diarrhoea, haematemesis (vomiting with blood), malaise (body weakness) and, at a later stage of disease, external haemorrhage (bleeding from orifices).

As of 11 January 2025, nine suspected cases were reported including eight deaths (case fatality ratio (CFR) of 89%) across two districts – Biharamulo and Muleba.  Samples from two patients have been collected and tested by the National Public Health Laboratory. Results are pending official confirmation. Contacts, including healthcare workers, are reported to have been identified and under follow-up in both districts.

The Bukoba district in Kagera region experienced its first MVD outbreak in March 2023, and zoonotic reservoirs, such as fruit bats, remain endemic to the area. The outbreak in March 2023 lasted for nearly two months with nine cases including six deaths.