A new genomic analysis published in Nature Medicine has identified the cause of the Ebola outbreak sweeping the Democratic Republic of the Congo (DRC): a fresh spillover of the virus from animals to humans, rather than the resurgence of a strain from earlier outbreaks.
Scientists from the DRC, Uganda, Belgium, and other institutions examined viral genetic sequences from 22 patients across the DRC and Uganda. Their findings confirmed the current strain is genetically distinct from Bundibugyo ebolavirus strains responsible for outbreaks in 2007 and 2012, pointing to a single, independent zoonotic transmission event that then spread through human contact. The specific animal source remains unidentified.
The outbreak, formally declared in mid-May but traced back to February through sequencing, has already claimed more than 2,000 lives among 4,449 confirmed cases, making it the fastest-spreading Ebola event on record. The World Health Organization has cautioned that, at current rates, it could surpass the toll of the 2014–2016 West African epidemic, which killed over 11,000 people.
Unlike the Zaire strain behind that earlier crisis, no licensed vaccine or targeted therapeutic currently exists for Bundibugyovirus, though experimental candidates are in development. Public health experts emphasize that while the outbreak originated from a single spillover event, its rapid spread is now driven almost entirely by human-to-human transmission—underscoring gaps in early detection and surveillance at the human-animal interface.
More than 100 healthcare workers have contracted the virus, with roughly 35 fatalities among responders. Several nations, including Rwanda, Uganda, and Bahrain, have imposed travel restrictions on visitors from affected regions as containment efforts continue.
Written By: Sayan Das
Graphics by: Pramit Hazra
