The World Health Organisation (WHO) has confirmed a suspected outbreak of Marburg Virus Disease in Tanzania, with the epicentre identified as the Kagera region.
In a statement released on Tuesday, WHO disclosed that the outbreak, which has resulted in eight deaths out of nine reported cases, remains of unknown origin. It noted that the risk of the outbreak is assessed as high at the national level due to several concerning factors, while the regional risk is also high owing to the strategic location of the Kagera region as an international transit hub.
The global health body, however, stated that there is currently no confirmed international spread, though concerns about its potential risks looms.
According to the statement, “On 10 January 2025, Six people were initially reported to have been affected, five of whom died. The cases exhibited symptoms such as headache, high fever, back pain, diarrhoea, haematemesis (vomiting with blood), malaise (body weakness), and external haemorrhage (bleeding from orifices) in later stages of the disease.”
“By 11 January 2025, nine suspected cases, including eight fatalities, had been reported across the districts of Biharamulo and Muleba, resulting in a case fatality ratio of 89 per cent. Samples from two patients were collected and tested by the National Public Health Laboratory, with results pending confirmation. Contacts, including healthcare workers, have reportedly been identified and are under follow-up in the affected districts.”
The Kagera region has a history of Marburg Virus Disease outbreaks, with its first recorded occurrence in the Bukoba district in March 2023. That outbreak lasted nearly two months, resulting in nine cases, six of which were fatal. Zoonotic reservoirs, such as fruit bats, remain endemic in the area.
WHO also highlighted measures taken to contain the outbreak, including the deployment of national rapid response teams to support investigations and response efforts. Surveillance activities have been intensified, with contact tracing ongoing, and laboratory samples from recent cases sent for confirmation. Additionally, a mobile laboratory has been established in Kagera region, and treatment units have reportedly been set up.
The health body stated, “The risk of this suspected Marburg Virus Disease outbreak is assessed as high at the national level due to several concerning factors. These include the high CFR of 89 per cent, involvement of healthcare workers among the suspected cases, geographic spread across two districts, and delayed detection and isolation of cases. More cases are expected to be identified as investigations continue.
“On regional risk, WHO noted that the Kagera region’s strategic location as a transit hub poses significant challenges. “The region’s proximity to Rwanda, Uganda, Burundi, and the Democratic Republic of the Congo raises concerns about cross-border transmission, particularly as some suspected cases have been reported near international borders.
“While Marburg Virus Disease is not easily transmissible, as it typically requires direct contact with the bodily fluids of symptomatic patients or contaminated surfaces, the possibility of exposed individuals travelling cannot be excluded. Enhanced surveillance and case management capacities at points of entry and borders are crucial, alongside close coordination with neighbouring countries to strengthen readiness capacities,” WHO emphasised.
It continued, “Globally, the risk is assessed as low, as Kagera region is neither close to Tanzania’s capital nor major international airports. However, the region’s connectivity through transportation networks and an airport linking to Dar es Salaam underscores the need for vigilance.
“Based on the current risk assessment, WHO advises against any travel and trade restrictions with the United Republic of Tanzania,” it concluded.
