The Bundibugyo strain of the Ebola virus: What do we know?

The World Health Organization (WHO) has declared a public health emergency of international concern due to an outbreak of the rare Bundibugyo strain of Ebola virus. The current outbreak is concentrated in the Democratic Republic of Congo (DRC) and Uganda, with over 100 suspected deaths and nearly 400 suspected infections reported as of Monday. The Bundibugyo strain was first identified in Uganda’s Bundibugyo province during an outbreak in 2007-2008, with a second outbreak occurring in the DRC in 2012. This strain has a fatality rate of 30-40%, lower than the more common Zaire strain, which can kill up to 90% of infected individuals. Transmission occurs through direct contact with bodily fluids from infected humans or animals, posing significant risks for healthcare workers, including a U.S. doctor infected in the current DRC outbreak. Symptoms of Bundibugyo infection begin with flu-like illness—fever, fatigue, muscle pain, headache, and sore throat—followed by vomiting, diarrhea, and internal/external bleeding. The WHO notes that early detection is critical, but initial testing in this outbreak failed to identify cases due to reliance on tests designed for other Ebola strains, delaying response efforts. No approved vaccines or drugs exist specifically for Bundibugyo, though experimental treatments like Merck’s Ervebo, Mapp Biopharmaceutical’s MBP 134, and NanoViricides’ NV-387 show potential. Public health measures remain the primary defense, including case detection, isolation, contact tracing, safe burials, and community engagement. Dr. Daniela Manno of the London School of Hygiene & Tropical Medicine emphasized that rapid implementation of these strategies, as seen in the 2014–2016 West Africa Ebola epidemic, is essential to controlling the current outbreak. Tests for Bundibugugyo do exist but are not widely used, contributing to delays in response. Dr. Matthew Kavanagh of Georgetown University noted that false negatives from initial testing allowed the virus to spread along transport routes and cross borders before detection. Efforts are now focused on scaling up appropriate diagnostics and deploying experimental interventions to curb further transmission.