New transmission from animals likely caused Congo-Uganda Ebola outbreak, study says

A new study suggests the ongoing Ebola outbreak in the Democratic Republic of Congo and Uganda resulted from a novel transmission from animals to humans, rather than from previous outbreaks linked to variants of the rare Bundibugyo species. Researchers from multiple countries examined the genetic makeup of virus samples from 22 patients in both nations and discovered the outbreak strain is genetically distinct from earlier Bundibugyo Ebola viruses that emerged in outbreaks in 2007 and 2012.

The findings, published in the journal Nature Medicine, indicate the outbreak likely originated from a fresh animal-to-human transmission event and subsequently spread among people. While the exact animal source remains unidentified, Ebola viruses are known to sporadically transmit from infected animals to humans. The genetic analysis confirmed that cases in Uganda are linked to the outbreak in Congo.

The study's authors emphasized that enhanced access to testing and virus sequencing could facilitate earlier detection of future Ebola outbreaks and enhance containment efforts. Despite the absence of an approved vaccine or treatment for Bundibugyo, candidate vaccines and treatments are currently under development. As of the latest government data, the outbreak, declared on May 15, has resulted in over 2,000 deaths and 4,381 confirmed cases.