The findings, published on Monday in the journal Nature Medicine, suggest the outbreak began with ​a fresh animal-to-human transmission event and was then ​spread between people. The study did not identify the animal source of ‌the outbreak, but Ebola viruses are known to spill over periodically from infected animals to humans. The genetic analysis helped confirm that cases detected in Uganda were linked to the ​outbreak in ​Congo. The study's authors said wider access to testing and virus sequencing could help detect future Ebola ​outbreaks earlier and improve efforts to contain them. The outbreak was declared on 15th May and has surpassed 2,000 deaths, ​with 4,381 confirmed cases so far, according to the latest government data.