Ebola Virus Disease

📺 Teaching Video:
https://youtu.be/K95Mc3ePTqw&list=PLOlpsJ0eDlASRw1LywI2iGfzDTqxlAYFJ

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Ebola Virus Disease
- Rare but severe illness caused by Ebola virus species
- Discovered in 1976; outbreaks mainly in sub-Saharan Africa
- Critical for healthcare providers to ensure early diagnosis, management, and infection control
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Etiology
- Ebola viruses: Filoviridae family, Orthoebolavirus genus
- Six species identified; four cause human disease (Zaire, Sudan, Taï Forest, Bundibugyo)
- Zaire ebolavirus most deadly with highest fatality rates
- Fruit bats likely the natural reservoir
- Transmission: Contact with infected animals or body fluids of infected humans
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Transmission Details
- Human-to-human via blood, feces, saliva, urine, vomit, breast milk, semen, etc.
- Entry through broken skin or mucous membranes (eyes, nose, mouth)
- Only contagious after symptom onset
- Surfaces and materials contaminated with fluids can spread infection
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Virus Behavior
- Targets immune cells: dendritic cells, macrophages
- Rapid spread via blood and lymphatic systems
- Virus evades early immune detection using glycoproteins
- Triggers "cytokine storm," leading to vascular leakage and organ failure
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Clinical Effects
- Direct endothelial damage increases vascular permeability
- Impaired coagulation leads to hemorrhagic symptoms
- Liver dysfunction and adrenal insufficiency worsen shock
- Fatal cases: High viral load, delayed immune response, DIC, shock
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Early Symptoms
- Incubation: 2–21 days (average 8–10 days)
- Early "dry" symptoms: 
  - Fever, severe fatigue, muscle/joint pain, headache, sore throat
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Progressive Symptoms
- "Wet" symptoms:
  - Severe diarrhea, vomiting, abdominal pain
- Other signs:
  - Chest pain, shortness of breath, confusion, hiccups, rash
- Bleeding manifestations in ~40% of patients
- Rapid progression to multi-organ failure and death in severe cases
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Diagnosis
- High suspicion needed with epidemiologic risk factors
- Confirmatory tests:
  - RT-PCR for viral RNA (gold standard)
  - Antigen capture tests, antibody ELISA, virus culture, electron microscopy
- Early RT-PCR negative? Repeat testing if suspicion remains
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Supportive Care
- Aggressive fluid and electrolyte replacement critical
- Symptomatic treatment for fever, nausea, diarrhea
- Nutritional support essential for recovery
- Monitor and manage complications: bleeding, shock, organ failure
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Therapeutics & Infection Control
- Investigational treatments:
  - Monoclonal antibodies (Inmazeb, Ebanga) improve survival
- Infection control:
  - Strict PPE use, safe injections, waste management, safe burials
  - Care in specialized Ebola Treatment Units (ETUs)
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Prognosis
- Mortality varies: 25–90%, average ~50%
- Zaire ebolavirus has highest fatality
- Early diagnosis and intensive supportive care improve survival
- Survivors often face long-term complications (Post-Ebola Syndrome)
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Prevention and Vaccination
- rVSV-ZEBOV (Ervebo) vaccine effective against Zaire ebolavirus
- Critical for outbreak control and protecting high-risk individuals
- Ongoing research for broader vaccines
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Summary
- EVD: High-mortality disease requiring urgent recognition and care
- Healthcare providers key to early detection, isolation, treatment
- Combined efforts in management, vaccination, and infection control essential to combat outbreaks

📺 Teaching Video:
https://youtu.be/K95Mc3ePTqw&list=PLOlpsJ0eDlASRw1LywI2iGfzDTqxlAYFJ