Ebola Symptoms
Ebola virus disease (EVD) progresses through distinct, well-defined phases. Recognising symptoms early and seeking treatment within the first 3 days dramatically improves survival outcomes. This guide follows WHO and CDC clinical criteria.
Disease Progression by Phase
Incubation Period
- › No visible symptoms (asymptomatic)
- › Virus actively replicating inside body
- › Person is NOT infectious to others
- › Critical window for contact tracing
- › Ring vaccination most effective at this stage
- › Average 8–10 days; up to 21 days possible
Early / Prodromal
- › Sudden onset high fever (>38.6 °C / 101.5 °F)
- › Severe frontal headache
- › Intense muscle and joint pain (myalgia)
- › Profound fatigue and weakness
- › Sore throat and difficulty swallowing
- › Loss of appetite
- › Begins to be contagious — isolation required
Acute / GI Phase
- › Profuse vomiting and watery diarrhoea
- › Severe abdominal cramps and pain
- › Diffuse maculopapular rash (trunk)
- › Persistent hiccups
- › Red eyes (conjunctival injection)
- › Chest pain and shortness of breath
- › Oedema (face, neck, scrotum)
- › Highly contagious — strict PPE required
Hemorrhagic / Severe
- › Internal and external bleeding
- › Bleeding from gums, nose, eyes, ears
- › Blood in vomit (hematemesis) and stool (melena)
- › Spontaneous bruising and petechiae
- › Acute kidney and liver failure
- › Neurological: confusion, coma, seizures
- › Septic shock and multi-organ failure
- › CFR: 40–90% without treatment
⚠ Emergency Warning Signs — Seek Immediate Care
If you have been in an outbreak area and develop these symptoms, contact health authorities immediately. Do not self-transport — call ahead so facilities can prepare isolation.
WHO Clinical Case Definition
Any person (alive or dead) who has had contact with a probable or confirmed case and has fever ≥38°C plus at least 3 other symptoms (headache, vomiting, diarrhoea, abdominal pain, bleeding, muscle pain, weakness).
Any suspected case evaluated by a clinician, or any deceased suspected case with an epidemiological link to a confirmed case but where laboratory confirmation was not possible.
Any suspected or probable case with a positive laboratory test: RT-PCR positive for Ebola virus RNA in blood or other body fluid samples.
Symptom Comparison by Ebola Strain
| Feature | Zaire (EBOV) | Sudan (SUDV) | Bundibugyo (BDBV) |
|---|---|---|---|
| Case Fatality Rate | 40–90% | 40–65% | 25–36% |
| Hemorrhagic symptoms | Common | Less common | Rare |
| Incubation range | 2–21 days | 2–21 days | 2–21 days |
| Approved vaccine | rVSV-ZEBOV ✓ | None | None |
| Approved treatment | Inmazeb / Ebanga | Supportive only | Supportive only |
| Major outbreaks | DRC, West Africa 2014 | Uganda 2022 | Uganda 2007 |
Post-Ebola Syndrome (PES)
Surviving Ebola does not mean full recovery. Up to 75% of survivors experience persistent health problems for months or years. These conditions are collectively termed Post-Ebola Syndrome.
Uveitis, cataracts, vision loss — most common complication in survivors
Arthralgia and myalgia persisting weeks to months after recovery
Headache, memory impairment, hearing loss, peripheral neuropathy
Profound fatigue and weakness for months post-discharge
PTSD, depression, anxiety — reported in >50% of survivors
Virus can persist in semen up to 18 months; sexual transmission risk post-recovery
Key Clinical Facts
Infectious only after symptom onset. Remains contagious in body fluids up to 7 days post-recovery. Virus persists in semen up to 18 months.
Direct contact with blood or body fluids of symptomatic/deceased person. NOT airborne. Healthcare workers and family caregivers at highest risk.
RT-PCR is gold standard. Antigen-RDT used in field settings. Results typically available in 3–6 hours. Negative result within 3 days of exposure does not rule out infection.
CFR drops below 40% with supportive care (IV fluids, electrolytes, oxygen) in first 3 days. Monoclonal antibodies (Inmazeb, Ebanga) reduce CFR to ~6% for Zaire strain.