Ebola virus disease
Ebola virus disease (EVD) is a serious and often fatal disease caused by the Ebola virus. There are five species of ebola viruses. EVD was previously called Ebola haemorrhagic fever.
Fruit bats are considered to be the natural host of Ebola virus, with outbreaks occurring among other species, such as chimpanzees, gorillas, monkeys and forest antelope from time to time. There have been more than 20 recorded outbreaks of EVD in Africa since the first in 1976. While there is evidence of one species of Ebola virus being present in animal populations in some parts of Asia, until 2014 there had been no reports of human illness outside of Africa. The 2014 outbreak in West Africa is the largest EVD outbreak reported occurring principally in Guinea, Sierra Leone and Liberia.
There is no evidence that Ebola virus is present in Australian bats or other animals. There have been no human cases of EVD in Australia.
- EVD is a serious illness, with a sudden onset of fever, muscle aches, weakness and headache.
- The next stage may include vomiting, diarrhoea, sore throat, rash and malfunction of the liver and kidneys.
- Cases may progress to multi-organ failure, sometimes with profuse internal and external bleeding.
- The average case fatality rate is around 50%. Case fatality rates have varied from 25% to 90% in past outbreaks. It is likely that this rate would be lower in a developed country like Australia with better equipped and resouced health facilities.
How is it diagnosed?
- EVD is confirmed by finding genetic material from the virus in the blood, throat or urine. Serological tests to look for antibodies to Ebola virus are also available.
- In Australia, testing to confirm EVD is done in a public health laboratory with special facilities to conduct the tests safely.
There is currently no specific treatment that is proven to be safe and effective for people who are sick with EVD and care is largely supportive. Good and early supportive care and the management of complications can be lifesaving. It is therefore crucial for the person who has been potentially exposed to the Ebola virus and becomes unwell to seek immediate medical advice.
- Ebola virus is initially introduced into the human population through direct contact between mucous membranes or broken skin and the blood, organs, secretions, or other bodily fluids of infected animals (often resulting from the hunting or preparation of forest animals, or ‘bushmeat’).
- Ebola virus then spreads from person-to-person via direct contact between mucous membranes or broken skin and:
- the body or bodily fluids (including but not limited to blood, urine, saliva, faeces, vomit and semen) of people with EVD, and the bodies of people who have died of EVD
- objects (e.g. needles, syringes) contaminated with blood or bodily fluids of people with EVD.
- Washing hands with soap and water can destroy the virus and prevent cross-contamination.
- It is important to note that people infected with Ebola virus do not become infectious to others until they have symptoms.
- Transmission through sexual contact may occur up to three months after the clinical recovery of males.
- Airborne transmission of Ebola virus between humans is not known to occur.
- There is no evidence that Ebola virus has been spread by coughing or sneezing, however large wet droplets may be infectious so precautions are taken to prevent transmission.
- Traditional burial ceremonies conducted in affected areas of Africa are a known high risk activity for transmission.
- Contracting EVD through food products is not known to occur. The amount of food coming to Australia from affected countries in Africa is very small and safe due to transport and food processing requirements.
Who is at risk?
People who are living in or travelling to and from EVD affected countries within Africa may be at risk of infection, however the risk of infection is low unless there has been direct exposure to the bodily fluids of an infected person or animal (alive or dead).
Caring for ill relatives is a known risk factor for infection, and healthcare workers, particularly those in resource poor settings with inadequate infection control measures are also at risk.
Once someone recovers from EVD, they can no longer spread the virus. However, Ebola virus has been found in semen for up to 3 months. Abstinence from sexual activity (including oral sex) is recommended for at least 3 months.
What should I do if I believe I may have been in contact with an infected person?
If you believe you have been in contact with an Ebola virus infected person, contact your local public health unit.
If you become ill or feel unwell while travelling in EVD affected countries, you should not wait until you arrive back in Australia to seek medical assistance. Instead you should see a doctor or go to the local emergency department in that country to work out why you are ill.
If you become ill or feel unwell in Australia and you have recently returned from an EVD affected country, or you have been in contact with an ill person who has recently returned from an EVD affected country, you should seek immediate medical attention. Before going to the doctor, it is important that you contact them by phone and mention your symptoms and which countries you have visited.
In Queensland, if you are unwell, before seeing a doctor or going to the hospital you should call 13 HEALTH (13 43 25 84) and mention your symptoms and which countries you have visited. 13 HEALTH will then make arrangements for an immediate health assessment.
- There is currently no vaccine widely available to prevent EVD.
- People should avoid direct exposure to the bodily fluids of an infected person or animal (alive or dead).
- People should also practice careful personal hygiene, including regular hand washing.
- Anyone travelling to affected areas to work or volunteer in a healthcare setting should seek advice (in Queensland you can call 13 HEALTH) and ensure they are fully informed about infection control procedures and recommendations.
For further information on EVD, including advice on current outbreaks please visit the Commonwealth Department of Health website.