Ebola virus disease is a rare zoonotic disease caused by infection with 1 of 5 species of Ebolavirus. Zaire ebolavirus, the species responsible for the current outbreak, was first discovered in 1976 near the Ebola River in Zaire (now the Democratic Republic of the Congo). Since then, a number of EVD outbreaks have been recognized, primarily confined to remote areas of East and Central Africa. The animal reservoir of ebolavirus is believed to be fruit bats. Zoonotic transmission can occur through direct contact with bats, primates, and duiker antelopes that have died from ebolavirus infection. Ebolavirus can spread among humans primarily through unprotected direct contact of skin (through breaks or microabrasions) or mucous membranes with blood or body fluids (eg, feces, saliva, urine, and vomit) of a person who is ill with EVD, or the corpse of a deceased patient who had EVD, or possibly with objects contaminated with the blood or body fluids of an infected person. The mean incubation period in the current outbreak is estimated at 11.4 days (typical range, 2-21 days).4,5 A person with ebolavirus infection is not contagious until symptoms are present. Currently, no specific therapeutics or vaccines are approved for EVD, and clinical management is focused on supportive care of complications (eg, hypovolemia and electrolyte abnormalities). Several investigational therapeutics are in development and some may be available for compassionate use or through enrollment in clinical trials in the future. Two investigational EVD vaccines are in Phase I trials in healthy adults.