Emergencies preparedness, response

Frequently asked questions on Ebola virus disease

Updated 14 July 2015

1. What is Ebola virus disease?

Ebola virus disease (formerly known as Ebola haemorrhagic fever) is a severe, often fatal illness, with a death rate of up to 90% caused by Ebola virus, a member of the filovirus family.

The Ebola virus was first identified in 1976 when 2 simultaneous outbreaks occurred, 1 in Yambuku, a village not far from the Ebola River in the Democratic Republic of Congo and the other in a remote area of Sudan.

The origin of the virus is unknown, but current evidence suggests that fruit bats (Pteropodidae) may be a host.

2. How do people become infected with the Ebola virus?

People become infected with Ebola either through contact with infected animals (usually following butchering, cooking or eating) or through contact with the bodily fluids of infected humans. Most cases are caused by human to human transmission which occurs when blood or other bodily fluids or secretions (stool, urine, saliva, semen) of infected people enters a healthy person’s body through broken skin or mucous membranes.

Infection can also occur if the broken skin or the mucous membranes of a healthy person comes into contact with items or environments contaminated with bodily fluids from an infected person. These may include soiled clothing, bed linen, gloves, protective equipment and medical waste such as used hypodermic syringes.

3. Who is most at risk?

During an outbreak, those at higher risk of infection are:

  • health workers;
  • family members or others in close contact with infected people;
  • mourners who have direct contact with bodies during burial rituals.

4. Why are mourners at burial ceremonies considered at risk of contracting Ebola?

Levels of Ebola virus remain high after death, thus bodies of those who have died from Ebola virus disease must be handled only by people wearing appropriate personal protective equipment and must be buried immediately. WHO advises that bodies of people who may have died from Ebola virus disease should be handled only by trained burial teams, who are equipped to properly bury the dead, safely and with dignity.

5. Why are health-care workers at greater risk of catching Ebola?

Health-care workers are at greater risk of infection if they are not wearing correct personal protective equipment (PPE) or are not applying infection prevention and control (IPC) measures when caring for patients. All health-care providers working at all levels of the health system – hospitals, clinics and health posts – should be fully informed about the disease and its mode of transmission and should follow recommended precautions strictly.

6. Can Ebola be transmitted sexually?

Sexual transmission of the Ebola virus, from males to females, is a strong possibility, but has not yet been proven. Less probable, but theoretically possible, is female to male transmission.

Studies have shown that Ebola virus can be isolated from semen up to 82 days after symptom onset and a recent case investigation identified genetic material from the virus 199 days after symptom onset. WHO has issued interim advice on sexual transmission of Ebola virus, available at: http://www.who.int/reproductivehealth/topics/rtis/ebola-virus-semen/en/)

7. What are the typical signs and symptoms of Ebola virus infection?

Ebola symptoms vary but sudden onset of fever, intense weakness, muscle pain, headache and sore throat are commonly experienced at the beginning of the disease (‘the dry phase’). As the disease progresses, people commonly develop vomiting and diarrhoea (‘the wet phase’), rash, impaired kidney and liver function, and in some cases, both internal and external bleeding.

8. How long does it take for people to develop symptoms after being infected?

The incubation period, or the time interval from infection to onset of symptoms, is from 2 to 21 days. People are not contagious until they develop symptoms. Ebola virus disease infections can only be confirmed through laboratory testing.

9. When should someone seek medical care?

A person with Ebola-like symptoms (fever, headache, muscle aches, headache, vomiting, diarrhoea) who has been in contact with living or dead people suspected to have had Ebola or has travelled to an area known to have cases of Ebola virus disease should seek medical care immediately.

10. Is there any treatment for Ebola?

Supportive care, especially fluid replacement therapy, carefully managed and monitored by trained health workers improves chances of survival. Other treatments being used to help people survive Ebola virus disease include, where available, kidney dialysis, blood transfusions, plasma replacement therapy.

There is currently no specific drug proven effective against the Ebola virus in humans but research into potential drug therapies is ongoing. Research into use of plasma and blood donated by survivors is also ongoing.

11. Can people with Ebola be cared for at home?

WHO does not advise families or communities to care for individuals with symptoms of Ebola virus disease at home. People with such symptoms should seek treatment in a hospital or treatment centre staffed by doctors and nurses equipped to treat Ebola virus disease.

If a person dies at home and is suspected of having died from Ebola virus disease, family and community members should refrain from handling or preparing the body for burial. The local health authorities should be contacted immediately and asked to send a dead body management team.

12. Can Ebola be prevented?

People can protect themselves from infection with Ebola virus following specific infection prevention and control measures. These include hand washing, avoiding contact with the bodily fluids of individuals who are suspected of or confirmed to have Ebola, and refraining from handling or preparing bodies of persons who are suspected of or confirmed to have died from Ebola.

13. Is there an Ebola vaccine?

It is hoped that a vaccine will be identified for large-scale use by the end of 2015. Two Ebola candidate vaccines are currently in the final stages of evaluation of their effectiveness (Phase III clinical trials). These trials are underway in Guinea and Sierra Leone. Other vaccines are in earlier stages of development.