Ebola Virus Disease

What is Ebola Virus Disease?

Ebola Virus Disease (EVD) is a severe, often fatal disease, caused by infection with one of the five Ebola virus strains. It is one of the most virulent diseases known to humans, and has an average fatality rate of between 50-90%. Symptoms of EVD include fever, intense weakness, muscle pain, headache and sore throat. As the disease progresses, it can cause vomiting, diarrhoea, rash, organ failure, and in some cases, bleeding from the eyes, ears and nose.

History and Prevalence

Since its discovery in 1976, the virus continues to cause periodic outbreaks of disease in sub-Saharan Africa. To date, there have been over 25 outbreaks, with the most recent occurring in West Africa in 2014-16. Several countries have been affected, with the highest number of cases and fatalities recorded in Guinea, Sierra Leone and Liberia.

Causes

EVD is caused by a virus that is transmitted through contact with the blood, secretions, or other bodily fluids of an infected animal or person. The virus strands responsible are: Zaire ebolavirus, Sudan ebolavirus, Bundibugyo ebolavirus, Taï Forest (previously Côte d'Ivoire) ebolavirus, and Reston ebolavirus.

Treatment and Prevention

Treatment for EVD is supportive, providing comfort and relief of symptoms. There are no specific medications or vaccines available to treat or protect against Ebola virus, but research is ongoing. Prevention-wise, avoiding contact with someone with EVD and avoiding contact with objects that may be infected with the virus is key.

Signs and Symptoms

Signs and symptoms of EVD usually begin between two and 21 days after contact with the virus, although it may take up to three weeks. Early signs and symptoms include:

• Fever
• Headache
• Joint and muscle aches
• Chills
• Weakness
• Fatigue

As the infection progresses, patients may experience bleeding from the gums, nose, eyes, or rectum, difficulty breathing and swallowing, and failure of the kidneys and liver. In the most severe cases, patients may develop bleeding from the skin and internal organs.