Lawrence Mapunda, Medard Beyanga, Nyambura Moremi, Jean N. Hakizimana, Doreen Kamori, Alfred Chacha, Edna E. Mgimba, Dennis Francis Mrosso, Ambele Mwafulango, Jackson Peter Mushumbusi, Ferdinand Ndunguru, Seif Abdul, Emmanuel Mkumbo, Maria E. Kelly, Céline Barnadas, Vida Mmbaga, Rogath Kishimba, Samwel Laizer, Ntuli Kapologwe, Michael Kiremeji, Erasto Sylvanus, Angela Samwel, Saumu Iddy Nungu, Emmanuel Achol, Julien A. Nguinkal, Hakimu Idris Lagu, Muna Affara, Florian Gehre, Calvin Sindato, Chacha Mangu, Elias N. Ntinginya, Saida Murugwa, Pawan Angra, Shannon Whitmer, George Mgomella, Mahesh Swaminathan, Wangeci Gatei, Dorcas Wanjohi, Sofonias Tessema, Yenew Kebede, Said Aboud, Charles Sagoe-Moses, Alex Magesa, Gerald Misinzo, Tumaini Nagu, Grace Magembe
Marburg virus (MARV) is the primary cause of Marburg virus disease (MVD), a severe hemorrhagic fever with a high case-fatality rate. The first reported MVD outbreak in Tanzania occurred in 2023, followed by a second outbreak in 2025, both within the Kagera region. During those MVD outbreaks, 174 suspected cases were identified; of those, 10 were laboratory confirmed. After complete genome assembly and bioinformatic analyses, we found the MARV strains of the 2023 and 2025 outbreaks to be closely related and clustered with MARV strains that caused outbreaks in Rwanda (2024) and Uganda (2014). The sequences from both MVD outbreaks in Tanzania showed >99.71% nucleotide identity, suggesting a possible single spillover event followed by limited human-to-human virus transmission. Further ecologic studies are essential to identify potential spillover events, but our findings indicate that closely related MARV strains circulate in Kagera, Tanzania, posing a risk for future outbreak recurrence.