Bundibugyo ebolavirus is a distinct species of the genus Ebolavirus. It was first recognized in 2007 after an outbreak in Bundibugyo District, Uganda, causing Ebola virus disease with lower case fatality than Zaire ebolavirus. It is a negative‑sense, single‑stranded RNA virus, enveloped, with a genome of about 19 kilobases encoding seven structural proteins.
Biology, Classification and Characteristics
Bundibugyo ebolavirus belongs to the family Filoviridae. Its genome is non‑segmented and encodes nucleoprotein (NP), virion protein 35 (VP35), VP40, glycoprotein (GP), VP30, VP24 and the RNA‑dependent RNA polymerase (L). The virus particles are filamentous, enveloped and contain a helical nucleocapsid. The species is classified along with Zaire, Sudan, Taï Forest, Reston and Bombali ebolaviruses under the genus Ebolavirus. Bundibugyo ebolavirus is thought to share an ecological niche with fruit bats, which are suspected reservoirs for ebolaviruses. The 2007 discovery came after a cluster of hemorrhagic fever cases in western Uganda; sequencing confirmed a new species distinct from Zaire and Sudan ebolaviruses. Serologic surveys have since detected antibodies in bat populations and human communities, suggesting periodic spillover. The virus causes Ebola virus disease with an incubation period of 2–21 days, presenting with fever, fatigue, muscle pain, vomiting, diarrhea and in severe cases hemorrhage and multi‑organ dysfunction. Case fatality rates for Bundibugyo ebolavirus outbreaks have been around 25–36 %, lower than those for Zaire ebolavirus but higher than for Sudan ebolavirus in some reports. There is no specific antiviral therapy; supportive care improves survival, and vaccines developed against Zaire ebolavirus may provide cross‑protection, but efficacy against Bundibugyo ebolavirus is under evaluation.
Outbreaks and Key Facts
The first known outbreak occurred in late 2007 in Bundibugyo District, Uganda, resulting in 149 confirmed and probable cases and 37 deaths. The outbreak was contained through rapid identification, isolation of patients and community engagement. In 2012, an outbreak in Isiro, Democratic Republic of the Congo, caused 36 confirmed and probable cases with 13 deaths. Genetic analysis showed that the Congolese strain was closely related to the Ugandan strain, indicating the virus may circulate in the region. Because Bundibugyo ebolavirus has lower case fatality rates than Zaire ebolavirus, its impact can be underestimated, but the disease still causes severe illness and requires prompt medical response. Healthcare workers are at risk during outbreaks; personal protective equipment, infection control and safe burial practices are critical. Ongoing surveillance in endemic areas and among bat populations aims to identify the natural reservoir. Research into vaccine candidates that include multiple ebolavirus antigens may improve preparedness for future outbreaks.
Bundibugyo ebolavirus is an important member of the Ebolavirus genus with distinct genetic and epidemiological features. While outbreaks have been limited, the virus remains a threat in Central Africa, and continued surveillance, research and public health preparedness are needed.
Related Terms: Zaire Ebolavirus, Sudan Ebolavirus, Taï Forest Ebolavirus, Reston Ebolavirus, Bombali Ebolavirus