Ebola (Ebola haemorrhagic fever)
Definition and classification
Ebola virus disease (EVD) is a severe viral haemorrhagic fever caused by orthoebolaviruses (notably Zaire ebolavirus).
In the UK EVD is managed as a contact high‑consequence infectious disease (HCID) and acute‑hospital practice follows the national ACDP/UKHSA Viral Haemorrhagic Fever (VHF) algorithm and guidance (Risk assessment and immediate management of viral haemorrhagic fevers - updated 13 Jan 2026) with clinical/public‑health summary guidance from UKHSA (Ebola overview - updated 4 Sep 2025).
(ACDP/UKHSA, 13 Jan 2026; UKHSA, 4 Sep 2025)
Key epidemiology and transmission facts
- Reservoir and source: zoonotic filoviruses; fruit bats are the likely natural reservoir with spillover from infected wildlife.
- Incubation period: 2-21 days (mean ~8-10 days). Patients are not infectious before symptom onset; infectiousness increases with clinical severity (vomiting, diarrhoea, bleeding). (UKHSA, 4 Sep 2025)
- Routes of transmission:
- Direct contact with infected body fluids (blood, vomitus, diarrhoeal stool, saliva, urine, sweat, breastmilk).
- Contaminated fomites.
- Sexual transmission from survivors due to viral persistence in immune‑privileged sites (semen may remain PCR‑positive for many months to >1 year).
- Respiratory droplet/airborne spread is not a major route, but a precautionary approach is advised for aerosol‑generating procedures (AGPs). (ACDP/UKHSA, 13 Jan 2026)