Ebola virus disease
Timeline of the disease
1976 – Ebola virus disease emerged, with outbreaks in the Democratic Republic of the Congo and Sudan
1979 – Ebola virus disappeared and wasn’t recognised again until 1994
1994 and onwards – further outbreaks in Central Africa happened with increasing frequency
March 2014 – the current outbreak (the largest yet) was confirmed in Guinea, West Africa
Ebola virus disease is a serious, usually fatal, disease for which there are no licensed treatments or vaccines. But for people living in countries outside Africa, it remains a very low threat.
Ebola was first identified in Africa in the mid-1970s. An outbreak that began in March 2014 was the most serious so far. By August 13 2014 it had killed more than 1,000 people across Guinea, Liberia, Sierra Leone and Nigeria.
In August 2014, a British nurse who was treating patients in Sierra Leone contracted the Ebola virus and was flown back to the UK for treatment in a London hospital. But experts studying the virus believe it is very unlikely the disease will spread within the UK. To understand why, read Why is the risk low for people in the UK?
Read on to find out:
- How do Ebola outbreaks start?
- How does Ebola spread among people?
- Who’s at risk?
- What are the symptoms?
- How is it treated?
- What’s the advice for healthcare and aid workers?
- What’s the advice for travellers?
- What if I think I might have Ebola in the UK?
- How is it diagnosed?
- Why is the risk low for people in the UK?
- I may have been on a flight with someone with Ebola. Am I at risk?
- If we get a case of Ebola in the UK, would we see an outbreak similar to West Africa?
- Is there a risk of Ebola transmission from illegal bushmeat?
- Why are there media reports of people in the UK being tested for Ebola?
How do Ebola outbreaks start?
It’s thought the Ebola virus has been living harmlessly in fruit bats for many years, building up in this population and spreading to other forest animals including chimpanzees and gorillas.
It’s likely the virus makes its way into people after they butcher or handle dead animals contaminated with the virus.
How does it spread among people?
People can become infected with the Ebola virus if they come into contact with the blood, body fluids or organs of an infected person.
Most people are infected by giving care to other infected people, either by directly touching the victim’s body or by cleaning up body fluids (stools, urine or vomit) that carry infectious blood.
Traditional African burial rituals have also played a part in its spread. The Ebola virus can survive for several days outside the body, including on the skin of an infected person, and it’s common practice for mourners to touch the body of the deceased. They only then need to touch their mouth to become infected.
Other ways people can catch Ebola are:
- touching the soiled clothing of an infected person, then touching their mouth
- having sex with an infected person without using a condom (the virus is present in semen for up to seven weeks after the infected person has recovered)
- handling unsterilised needles or medical equipment that were used in the care of the infected person
A person is infectious as long as their blood, urine, stools or secretions contain the virus.
Ebola virus disease is generally not spread through routine social contact (such as shaking hands) with patients who do not have symptoms.
The virus is not, for example, as infectious as diseases like the flu, as airborne transmission is much less likely. You’d need to have close contact with the source of infection to be at risk.
Who is at risk?
Anyone who cares for an infected person or handles their blood or fluid samples is at risk of becoming infected. Hospital workers, laboratory workers and family members are at greatest risk.
Strict infection control procedures and wearing protective clothing minimises this risk – see What’s the advice for healthcare workers?. Simply washing hands with soap and water can destroy the virus.
What are the symptoms?
An infected person will typically develop a fever, headache, joint and muscle pain, sore throat, and intense muscle weakness. These symptoms start suddenly, between 2 and 21 days after becoming infected, but usually after 5-7 days.
Diarrhoea, vomiting, a rash, stomach pain and impaired kidney and liver function follow.
The patient then bleeds internally, and may also bleed from the ears, eyes, nose or mouth.
Ebola virus disease is fatal in 50-90% of cases. The sooner a person is given care, the better the chances that they will survive.
How is it treated?
There’s currently no licensed treatment or vaccine for Ebola virus disease, although potential new vaccines and drug therapies are being developed and tested.
Patients need to be placed in isolation in intensive care. Dehydration is common, so fluids may be given directly into a vein (intravenously). Blood oxygen levels and blood pressure need to be maintained at the right level and body organs supported while the patient’s body fights the disease and any other infections are treated.
ZMapp is an experimental treatment that can be tried, although it has not yet been tested in humans for safety or effectiveness. The product is a combination of three different antibodies that bind to the protein of the Ebola virus. Read more about ZMapp.
What’s the advice for healthcare and aid workers?
Any area affected by an outbreak should be immediately quarantined and patients treated in isolation.
Healthcare workers need to avoid contact with the bodily fluids of their infected patients by taking the following precautions:
- wear face masks, goggles, gowns and gloves
- take extra care when handling blood, secretions and catheters and when connecting patients to a drip
- disinfect non-disposable medical equipment before re-use
- sterilise and dispose of used needles and disposable equipment carefully
- properly dispose of any secretions or body waste from the patient
- carefully and frequently wash hands with soap and water (alcohol hand rub if soap isn’t available)
- wash disposable gloves with soap and water after use, dispose of them carefully, then wash hands
What’s the advice for travellers in at-risk areas?
Following these simple precautions will minimise your risk of catching Ebola virus disease:
- don’t handle dead animals or their raw meat
- don’t eat ‘bushmeat’
- avoid contact with patients who have symptoms
- avoid having sex with people in risk areas; use a condom if you do
- make sure fruit and veg is washed and peeled before you eat it
- wash hands frequently using soap and water (alcohol hand rubs when soap is not available), as this destroys the virus
If you think you or a family member has symptoms of Ebola infection:
- visit a healthcare provider immediately and inform them that you may have had contact with the Ebola virus (the nearest Embassy or Consular Office can help you find a provider in the area)
- limit contact with others and avoid all other travel
It’s more likely that the cause is another disease such as malaria, but you may need to be tested for Ebola as a precaution.
What if I think I might have Ebola in the UK?
If you feel unwell with symptoms such as fever, chills, muscle aches, headache, nausea, vomiting, diarrhoea, sore throat or rash within 21 days of coming back from Guinea, Liberia or Sierra Leone, you should stay at home and immediately telephone 111 or 999 and explain that you have recently visited West Africa.
These services will provide advice and arrange for you to be seen in a hospital if necessary so the cause of your illness can be determined.
There are other illnesses that are much more common than Ebola (such as flu, typhoid fever and malaria) that have similar symptoms in the early stages, so proper medical assessment is really important to ensure you get the right diagnosis and treatment.
It is also really important that medical services are expecting your arrival and calling 111 or 999 will ensure this happens.
How is it diagnosed?
It’s difficult to know if a patient is infected with Ebola virus in the early stages as symptoms such as fever, headache and muscle pain are similar to those of many other diseases.
But specialist infection clinicians will make expert judgements on what the most likely diagnosis is based on the patient’s history.
If Ebola is considered a possibility on this basis, then a person would be tested for the disease.
Samples of blood or body fluid can be sent to a laboratory to be tested for the presence of Ebola virus, and a diagnosis can be made rapidly.
A suspect case would be isolated in a side room so as to minimise contacts with other people while they are being tested. It is only if this test is positive that the case is considered to be ‘confirmed’.
If the test is positive then they will be transferred to a hospital-based high-level isolation unit.
If the result is negative, doctors will test for other diseases such as malaria, typhoid fever and cholera.
Why is the risk low for people in the UK?
The likelihood of catching Ebola virus disease is considered very low unless you’ve travelled to a known infected area and had direct contact with a person with Ebola-like symptoms, or had contact with an infected animal or contaminated objects.
There has been just one imported case of Ebola in the UK. While it is possible that more people infected with Ebola could arrive in the UK on a plane, the virus is not as easily transmitted as a respiratory virus such as influenza.
In past outbreaks, infection control measures have been very effective in containing Ebola within the immediate area. The UK has a robust public health system with the trained staff and facilities necessary to contain cases of Ebola.
Advice has been issued to the Border Force to identify possible cases of Ebola and there are procedures in place to provide care to the patient and to minimise public health risk to others.
Also, Ebola victims do not become infectious until shortly before they develop symptoms. The disease then progresses very rapidly. This means infectious people do not walk around spreading the disease for a long period.
It typically takes 5-7 days for symptoms to develop after infection, so there is time to identify people who may have been exposed, put them under surveillance and if they show symptoms, quarantine them.
Flight crew are trained to respond swiftly to any passengers who develop symptoms during a flight from Africa. They will take measures to reduce transmission on board the plane. But this event is very unlikely, and so far there have been no documented cases of people catching the disease simply by being in the same plane as an Ebola victim.
I may have been on a flight with someone with Ebola. Am I at risk?
You cannot catch Ebola through social contact or by travelling on a plane with someone who is infected, without direct contact with the blood or body fluids of an infected person.
Cabin crew identifying a sick passenger with suspicion of infectious disease on board, as well as ground staff receiving the passenger at the destination, would follow theInternational Air Transport Association guidelines for suspected communicable diseases (PDF, 37kb).
If there is someone unwell on board a flight, the pilot of the aircraft is legally required to inform air traffic control. Arrangements will be made for medical assessments for the person on arrival. The exact arrangements will depend on the airport involved. The local Public Health Team would be alerted if there was a possibility that the individual was suffering from an infectious disease so that appropriate public health action could be initiated.
If we get a case of Ebola in the UK, would we see an outbreak similar to West Africa?
While the UK might see cases of imported Ebola, this is extremely unlikely to result in a large outbreak in the UK. England has a world class healthcare system with robust infection control systems and processes and disease control systems that have a proven record of dealing with imported infectious diseases.
Is there a risk of Ebola transmission from illegal bushmeat?
The risk to the UK population of acquiring Ebola virus from bushmeat is very low.
It is illegal to import bushmeat into the UK. Cooking will kill the virus, but there is some risk in handling raw bushmeat and the Food Standards Agency advice has always been that people should avoid illegal bushmeat as you can never be certain of its safety.
Why are there media reports of people in the UK being tested for Ebola?
Public Health England has advised frontline medical practitioners to be alert to Ebola in those returning from affected areas. An increase in testing following such advice is to be expected.
To date all those tested have been negative. The initial symptoms of Ebola are similar to a number of other far more common diseases such as malaria and dengue fever.