Ebola

Strains

• Zaire ebolavirus (EBOV)
• Sudan ebolavirus (SUDV)
• Bundibugyo ebolavirus (BDBV)
• Taï Forest ebolavirus (TAFV)
• Reston ebolavirus (RESTV)
• Bombali ebolavirus (BOMV)

Transmission

• Direct contact with blood, body fluids (saliva, vomit, urine, feces, breast milk, semen) of infected people
• Contact with surfaces or objects contaminated with body fluids of infected persons
• Animal-to-human spillover via fruit bats (Pteropodidae) and infected non-human primates
• Traditional burial and funeral practices involving contact with the deceased
• Nosocomial transmission in healthcare settings without adequate infection control
• Sexual transmission possible — virus can persist in semen for months after recovery

Treatment

Two FDA-approved monoclonal antibody therapies for Zaire ebolavirus: Ebanga (Ansuvimab, mAb114) and Inmazeb (REGN-EB3, atoltivimab/maftivimab/odesivimab). Supportive intensive care: fluid replacement, electrolyte balance, oxygen, blood pressure support. No approved treatment for non-Zaire strains.

Vaccine status

Ervebo (rVSV-ZEBOV-GP, Merck) approved by FDA/EMA for Zaire ebolavirus since 2019, used widely in outbreak response (ring vaccination). Sudan ebolavirus vaccine candidates (e.g. cAd3-EBOZ, ChAd3-SUDV) in advanced trials and emergency deployment but not yet WHO-prequalified. No vaccine for other strains.

Endemic regions

• Democratic Republic of the Congo — Zaire ebolavirus (recurring outbreaks since 1976, 15+ outbreaks)
• Uganda — Sudan ebolavirus and Bundibugyo ebolavirus (multiple outbreaks since 2000)
• Sudan — Sudan ebolavirus (original 1976 outbreak)
• Guinea, Liberia, Sierra Leone — Zaire ebolavirus (2014-2016 West Africa epidemic, 11,300+ deaths)
• Republic of Congo, Gabon — Zaire ebolavirus (historical outbreaks)
• Côte d'Ivoire — Taï Forest ebolavirus (single 1994 case)