Actually, during the Ebola Reston crisis, four human beings did contract the virus. Three developed minor headaches and one person had a heart attack (he died some hours after the cardiac arrest, which is believed to have been brought on by the virus and, therefore, gives him the distinct- and posthumous- honor of being the first US victim of Ebola on American soil, this honor subdued by the fact that he did not expire from classic ebola symptoms).
The Centers for Disease Control CDC and United States Army Medical Research Institue of Infectious Diseases (USAMRIID) both worked together to track down the origin of Ebola Reston, which was suspected to be a filovirus (airborne bug). Of particular note is the rumor that the incident at Reston was the inspiration for the movie "Outbreak."
Ebola Reston had a kill ratio of 90%, like the other strains, but appeared to burn through the monkey stock in a matter of days rather than weeks. The incredibly fast motion of Ebola Reston makes it the most lethal strain so far. That four humans contracted it makes it cross-species capable, which scares the living hell out of most medical facilities, but the capacity to jump species is underscored by the apparent fact that Ebola Reston's symptoms in the human species are atypical of most other Ebola strains.
Source: The Hot Zone, by Richard Preston (Random House)