Skip to Main Content

For further information, see CMDT Part 34-05: Viral Hemorrhagic Fevers

KEY FEATURES

Essentials of Diagnosis

  • Early stage EVD presents as a nonspecific febrile illness

  • Later stage EVD typically includes severe gastrointestinal symptoms, followed by neurologic symptoms and hypovolemic shock

  • Hemorrhagic manifestations occur late in course

  • Uveitis is prominent ocular finding

  • Travel and contact history from an Ebola-affected country raise suspicion

  • Diagnosis is confirmed by detection of virus with a real-time polymerase chain reaction

General Considerations

  • Genus Ebolavirus is a single-stranded RNA virus in the Filoviridae family

  • Fruit bats are possible reservoirs for Ebolavirus

  • Zoonotic transmission to humans occurs via contact with the reservoir or an infected primate

  • Transmission

    • Occurs from direct contact with infected body fluids

    • Virus must enter the body via mucous membranes, nonintact skin, sexual intercourse (virus has been detected in semen up to 9 months after recovery from infection), breastfeeding, or needlesticks

    • Prior to symptoms, Ebola is not transmitted

    • Even at symptom onset, the risk of transmission is low but increases over time

  • Ebola has a 2- to 21-day incubation period (average is 8–10 days)

  • The estimated case fatality rate is 60%

Demographics

  • The first Ebola outbreak occurred in 1976 as a simultaneous epidemic in the Democratic Republic of Congo and South Sudan

  • The number of EVD cases spread rapidly starting in 2014

    • At least 10 countries have been affected, especially Guinea, Liberia, and Sierra Leone

    • Many cases and deaths in these countries occurred among health care workers

  • Countries with effective viral containment as of 2022 include Sierra Leone and Liberia

CLINICAL FINDINGS

Symptoms and Signs

  • Early-stage EVD

    • Headache

    • Weakness

    • Dizziness

    • Fever

    • Malaise, fatigue

    • Myalgia, arthralgia

  • Later-stage EVD (after 3–5 days)

    • Abdominal pain, severe nausea, vomiting, and diarrhea accompanying the febrile illness

    • This stage of the illness may continue for a week; neurologic symptoms gain prominence

    • Encephalitis is commonly observed and includes

      • Confusion

      • Slowed cognition

      • Agitation

      • Occasional seizures

    • Hypovolemic shock develops in most patients

    • However, hemorrhagic manifestations (gastrointestinal bleeding, diffuse mucosal bleeding, conjunctival bleeding) develop in only 1–5% of patients

    • Respiratory symptoms (ie, cough) are not typical, although interstitial pneumonia and respiratory failure have been reported

Differential Diagnosis

  • Varies with the stage of illness

  • Early-stage EVD

    • Malaria, typhoid, and other viral illnesses

    • Viral hepatitis

    • Toxins

    • Leptospirosis

    • Rickettsial diseases

  • In later stage EVD

    • Bacterial, viral, and parasitic illnesses, including cholera

    • In children, rotavirus infection, which can present with severe gastroenteritis and shock

    • Encephalitis must be differentiated from the confusion associated with uremia

  • Hemorrhagic manifestations could be due to leukemia, thrombotic thrombocytopenic purpura, hemolytic-uremic syndrome, or disseminated intravascular coagulation (DIC)

  • Travel and contact history are crucial when considering the differential diagnosis in areas where Ebola is not endemic

DIAGNOSIS

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.

  • Create a Free Profile