Ebola first appeared in 1976 in two simultaneous outbreaks in Nzara, Sudan, and in the Yambuku, Democratic Republic of Congo. The latter was in a village situated near the Ebola River, from which the disease takes its name.

Following the first ever Ebola patient on American soil, Dr. Kent Brantly, 33, Nancy Writebol, 59, landed Tuesday at Dobbins Air Force Base. After traveling from Monrovia, Liberia, Writebol headed for treatment in a special isolation unit at Emory University Hospital, located near the U.S. Centers for Disease Control and Prevention in Atlanta, GA.

The Emory isolation unit, designed to optimize care for those with highly infectious diseases, is one of only four of its kind in the United States.

Just as the groundbreaking arrival of both Ebola patients, another first is the use of an experimental drug in their treatment, ZMapp, developed by a San Diego-based biotech firm. Despite never being subjected to clinical trials, the medication is garnering much attention.