What Are Ebola Viruses?

The Ebola virus is part of a family of Filoviruses which can cause a devastating and often fatal disease in humans. Imported macaques have been implicated in outbreaks of Ebola suptype Reston (Ebola-R) in facilities in the United States beginning in 1989. Outbreaks of Marburg virus exposure occurred in Germany and Yugoslavia which were also from imported macaques into those countries. Nonhuman primates are unlikely to be a reservoir of Ebola virus since experimental or natural infection is quickly fatal.

Routes of Infection

Humans can become infected with filoviruses mainly by droplets and body fluid fomites. Filoviruses form infectious aerosols. Transmission of Marburg virus between animals and humans has usually been the result of contact with infected tissues.


The relative risk of coming into contact with a nonhuman primate contaminated with Ebola or Marburg virus is extremely low; however, nothing is absolute. Most nonhuman primates, initially, are wild-caught animals.


Prevention is the use of quarantine facilities approved by the CDC and the use of appropriate biosafety programs for imported macaques and other nonhuman primates, especially after receipt from endemic areas. The efficacy of the measures is based on the suppositions that filoviruses often result in significant disease in nonhuman primates held in quarantine; they are not latent or chronic diseases; and, as such, would be found during quarantine procedures.