Ebola disease outbreaks can come from wildlife or past outbreaks, not just animals. Researchers looked at 35 outbreaks from 1976 to 2022 to find out where they started. They found that some outbreaks were caused by the virus spreading between people, not just from animals. Bigger outbreaks were more likely to spread between people again. Most outbreaks happened in hospitals. Knowing this can help stop future outbreaks by testing more people and watching out for groups that could get sick again.