Forests play a key role in infectious diseases that affect humans. Five fruit bat species have a significant link to Ebola virus transmission and deforestation in their natural habitats in African rainforests. Deforestation of these areas increases the risk of Ebola outbreaks by bringing bats that may carry the virus into closer contact with human populations. Ocean-atmosphere oscillations like the Pacific Decadal Oscillation can also predict periods of higher Ebola outbreak risk, giving observers up to a year of advance notice to prepare prevention and response efforts.