Ebola virus disease (Ebola) is caused by a group of viruses known as orthoebolaviruses (formerly ebolavirus). Three of these viruses cause severe illness in people, presenting with a clinically-similar viral hemorrhagic fever:
- Ebola virus (EBOV) [Orthoebolavirus zairense, previously Zaire ebolavirus]
- Sudan virus (SUDV) [Orthoebolavirus sudanense, previously Sudan ebolavirus]
- Bundibugyo virus (BDBV) [Orthoebolavirus bundibugyoense, previously Bundibuygo ebolavirus]
A fourth virus, Taï Forest virus (TAFV, Orthoebolavirus taiense) has caused a single recorded case of non-lethal human disease. Historical case fatality rates have varied significantly; the average fatality rate is approximately 50%. In outbreaks casused by Ebola virus, fatality rates have often ranged from 70–90%, though actual mortality may vary depending on outbreak conditions, timing of care, and available therapeutics. Ebola is transmitted through direct contact (via broken skin or mucous membranes) with infected bodily fluids—such as blood, vomit, urine, feces, saliva, sweat, semen or breast milk—or with surfaces or materials contaminated with such fluids.
Ebola was first recognized in 1976 in near-simultaneous outbreaks in what are now the Democratic Republic of Congo (formerly Zaire) and South Sudan (formerly Sudan). Since then, there have been more than 35 documented outbreaks, primarily in Central and West Africa.
Many public health laboratories in the US can conduct testing for the Ebola using tests deployed through the Laboratory Response Network and/or using commercially available assays. APHL also collaborates with the US Centers for Disease Control and Prevention (CDC) and African Society for Laboratory Medicine (ASLM) to develop guidance, implement training and provide necessary support for laboratories outside the US to ensure they are able to perform safe, high quality and efficient testing.
