Ebola Virus

Snapshot

A 32-year-old medical assistant presents to a clinic in Uganda with fevers, generalized myalgias, and headaches. She reports also having nausea and blood-tinged vomiting. She had traveled to Uganda to volunteer at a hospital and has been working there for a month. She reports that the team had treated several patients for presumed flu, but laboratory testing revealed Ebola. On physical exam, she has a petechial rash on her chest. Appropriate isolation precautions are taken.

Introduction

Classification
- ebola virus
  - an enveloped, linear, non-segmented, negative-sense, single-stranded RNA virus
  - filovirus with a helical capsid
  - transmission via direct contact with infected human body fluids (including post-mortem)
  - reservoirs are humans or infected animals (bats, pigs, or primates)
  - causes hemorrhagic fever
Epidemiology
- incidence
  - most common in Africa
- risk factors
  - travel to endemic countries
  - occupational exposure
  - sick contacts
Pathogenesis
- the virus targets endothelial cells, hepatocytes, phagocytes, and dendritic cells
- after an incubation period up to 21 days, the virus will disseminate via the lymphatics and cause multiorgan failure
Prevention
- vaccines are under development
Prognosis
high mortality rate

Presentation

Symptoms
- flu-like symptoms
  - high fever
  - myalgia
  - headache
- nausea and vomiting
  - may have hematemesis
- diarrhea
  - may have melena
Physical exam
- petechial rash
- can be hemorrhagic if the disease progresses to disseminated intravascular coagulopathy (DIC) and shock
  - bleeding from puncture sites
conjunctival injection

Studies

Labs
- thrombocytopenia
- hepatic transaminitis
- detection of viral RNA on reverse-transcriptase polymerase chain reaction (RT-PCR)
Making the diagnosis
diagnosis based on clinical presentation and detection of viral RNA on RT-PCR

Differential

Yellow fever
- distinguishing factors
  - presents with jaundice and scleral icterus with minor hemorrhage
  - transmission via mosquitoes
Dengue fever
- distinguishing factors
  - also presents with hemorrhage
  - blanching confluent erythematous maculopapular rash with lymphadenopathy
transmission via mosquitoes

Treatment

Management approach
- immediate isolation of the patient
- mainstay of treatment is supportive
Conservative
- supportive care
  - indication
    - all patients
  - modalities
    - correct electrolyte abnormalities
    - hydration of blood transfusion
reversal of coagulopathy

Complications