Ebola is a viral infection, which mainly occurs in West and Equatorial Africa. There is as yet no vaccine or cure for Ebola, and about 4 out of 10 of those infected die of the disease. The risk of becoming infected with Ebola in the UK is very small.
Ebola is spread by close contact with an infected person. People with Ebola become infectious when they have symptoms. The risk of Ebola in the UK is only for people who have had close contact with someone who is already infected with Ebola, either by:
- Travel to a country affected by Ebola; or
- Close contact with someone who has returned from an infected country and has Ebola infection, although only once they have symptoms.
What is Ebola?
Ebola is a viral infection. Ebola infection was first recognised in 1974, with outbreaks in the Democratic Republic of the Congo and in Sudan. Since 1994 there have been further outbreaks of Ebola infection in Central Africa. The recent outbreak in West Africa is the largest recorded outbreak and was first confirmed in Guinea in March 2014.
How can I become infected with Ebola?
People 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 either by touching the patient's body or by cleaning up an infected person's body fluids (eg, blood, stools (faeces), urine, vomit, saliva, sweat, breast milk or semen). A person is infectious as long as their blood, urine, stools or secretions contain the virus.
You need to have close contact with a person infected with Ebola to be at risk of infection. People infected with Ebola do not pass on infection (become infectious) until they develop symptoms, although if they recover they can remain infectious for a little while afterwards.
Traditional rituals to honour the dead have played a part in the spread of Ebola. The virus can survive for several days outside the body, including on the skin of an infected person. It is common practice for mourners in Africa to touch the body of the dead person.
People can also become infected by having sex with an infected person without using a condom. Ebola virus can stay in semen for up to seven weeks after the infected person has recovered.
A few people in countries where Ebola is present in the animal population have acquired Ebola from contact with infected animals, including fruit bats (who may carry the disease), or from touching or eating other animals that have died of the disease.
Am I at risk of Ebola infection?
The risk of becoming infected with Ebola in the UK is extremely low. However, there is a risk of Ebola infection for anyone travelling to an infected country or anyone who comes into close contact with an infected person. This risk was greater for travellers from West Africa (particularly Sierra Leone) during the 2014-2016 epidemic. That epidemic is now over and the countries where it occurred have developed surveillance systems in order to spot new cases early, if they occur.
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. Patients who are sick are extremely infectious.
Although the UK might see cases of imported Ebola, this is extremely unlikely to result in a large outbreak in the UK. The UK has a very effective public health system and measures have been put in place to identify any infected person at the earliest opportunity. Healthcare staff have been made aware of how to deal with any person with possible Ebola infection. Special hospital isolation units have been made available.
Why was there an outbreak in 2014-2016?
The outbreak of 2014-2016 was the first time Ebola infection had spread into West Africa. In countries nearer the Equator there had been Ebola outbreaks before, so the country was alert for new cases and had well-developed testing systems and isolation wards. This meant that when there were outbreaks of Ebola they remained small and localised; numbers affected often did not rise above double figures. They also tended to be in remote, rural areas, away from cities, where local people had contact with forest animals.
When Ebola spread into West Africa, by contrast, countries were not expecting it. To make things worse, a long Civil War in Sierra Leone had left its public health systems weakened. Staff had not seen Ebola before and systems for testing cases or for isolating those affected were not in place. The local population was not fully aware of Ebola and did not at first understand or accept the need to isolate affected family members or to avoid touching deceased friends and relatives.
When the reason for the outbreak was understood, countries outside West Africa wanted to send help. However, it took time to set up a system which would mean that health professionals going into the country could do so without immediately contracting the infection themselves.
All of these reasons contributed to the size and length of the outbreak. It is also possible that the virus itself changed during the epidemic, becoming more infectious.
The 2014-2016 outbreak infected over 26,000 people, of whom around about 4 out of every 10 died. It was eventually contained, through improved public health and hospital care and with the involvement of the population in preventing spread. As a result of this, West Africa is now much better prepared and countries on the edge of the Ebola areas (areas in which Ebola is present in the wild fruit bats) are alert to possible spread. It is hoped that this means that a future outbreak would be contained much more quickly.
How can Ebola infection be prevented?
Any person suspected of being infected with Ebola should be isolated to prevent any contact with other people.
Anyone in contact with an infected person should:
- Wear personal protective equipment, including face masks, goggles (face visors may be preferred), gowns and gloves.
- Carefully and frequently wash hands with soap (or alcohol hand rub) and water.
- Wash disposable gloves with soap and water after use, dispose of them carefully and then wash hands.
Healthcare staff also need to make sure that any equipment is properly disinfected and sterilised. Extreme care must also be taken when disposing of needles and any body fluids from the infected person.
To reduce the risk of Ebola infection, travellers to affected countries should very carefully keep to the following advice:
- Don't handle dead animals or their raw meat.
- Don't eat 'bush meat' (meat from wild animals).
- Avoid contact with any person who may have any symptoms of Ebola infection.
- Do not have sex with anyone in or from a risk area (always use a condom if you do have sex).
- Make sure fruit and vegetables are washed and peeled before eating.
- Wash hands frequently using soap and water to destroy the virus.
There is currently no proven vaccine to prevent Ebola infection but a great deal of research is currently trying to develop an effective vaccine.
What are the symptoms?
An infected person will usually develop a high temperature (fever), severe headache, joint and muscle pain, sore throat, and muscle tenderness and weakness. These symptoms begin suddenly, starting between 2 and 21 days after becoming infected.
An infected person may then develop diarrhoea, sickness (vomiting), a rash, stomach pain and reduced kidney and liver function. Bleeding inside the body and also bleeding from the ears, eyes, nose or mouth may occur.
What if I think I might have Ebola in the UK?
If you feel unwell with any of the symptoms mentioned above within 21 days of coming back from any infected area of the world you should:
- Stay at home; and
- Immediately telephone 111, or your local emergency services number (999 in the UK, 911 in the USA, 112 in parts of Europe) and explain that you have recently visited a country with active Ebola infection and may have been exposed.
These services will provide advice and arrange for you to be seen in a hospital if necessary to find out what is causing your illness. It is essential to call for advice and not just turn up at a hospital or your GP surgery, where you could infect others.
How is Ebola diagnosed?
If Ebola is considered a possibility then tests will include samples of blood or body fluid sent to a laboratory to be tested for Ebola virus. A diagnosis can be made very quickly. If the test is positive then the infected person will be transferred to an approved hospital isolation unit.
If Ebola is considered a possibility then whilst test results are being awaited you will need to be isolated. Health professionals looking after you will need to wear special protective clothing.
How is Ebola treated?
People infected with Ebola need to be placed in isolation in intensive care.
There is currently no proven treatment to cure Ebola infection, although potential treatments are being developed and tested. Several possible medicines were used during the recent outbreak. ZMapp is the most widely known. It seemed to help survival in some cases, although trials about how effective it is have been inconclusive. Plasma from survivors is also sometimes given, again with mixed results.
Supportive care is very important. This includes fluids introduced into the body through a vein (intravenously), use of oxygen and, sometimes, blood products. The sooner supportive care is provided, the better the chances of survival.
What is the outcome (prognosis)?
Ebola virus disease is fatal in about 4 out of 10 cases. Some people who have recovered from Ebola have developed long-term complications, such as joint or vision problems.
Dr Colin Tidy
Dr Mary Lowth
Dr Laurence Knott