The Bundibugyo virus challenge: why is this Ebola disease outbreak different?

On May 15, 2026, the Democratic Republic of Congo's Ministry of Health officially declared an Ebola disease outbreak in the northeast of the country, where Médecins Sans Frontières (MSF) teams are operating. 

Since then, authorities have reported nearly 500 suspected cases and more than 130 deaths across multiple health zones. On the same day, Uganda announced the virus had crossed its borders. The outbreak is caused by the Bundibugyo virus — rarer and one for which no vaccine or treatment has been approved yet. Here is what we know about the unfolding crisis in the DRC and Uganda.