Ebola virus disease first appeared in 1976 in two outbreaks in central Africa. The current west Africa outbreak beginning in 2014 is the largest on record. Ebola virus is a rare but deadly virus that causes bleeding and damages organs and the immune system. It spreads through contact with infected animals like bats or non-human primates, or through contact with a sick or dead human's bodily fluids. Health care providers and family members in close contact with patients have the highest risk of infection. While there is no approved vaccine or treatment, experimental treatments aim to manage symptoms and replace fluids and blood.