Ebolavirus disease (EVD)
What is Ebolavirus disease?
Ebolavirus disease (EVD), commonly called Ebola, is a serious and often fatal disease caused by Ebolavirus.
The virus can cause disease in humans, other primates (apes and monkeys) and some other animal species. Since Ebolavirus was first identified in 1976, there have been occasional small outbreaks of disease in humans in rural areas of sub-Saharan and central Africa. The recent outbreak in West Africa, which commenced in 2013, is the largest ever recorded and the first to spread to major urban areas and to multiple countries.
Scientists have identified four species of Ebolavirus across the central part of Africa and believe that it occurs naturally in fruit bats. A fifth species of the virus has been identified in monkeys in parts of Asia but does not appear to cause human disease.
There is no evidence that Ebolavirus occurs in bats or other animals in Australia.
How is it spread?
Humans may become infected with Ebolavirus through direct contact with the blood, bodily fluids or tissues of an infected animal, usually during hunting and preparation of ‘bushmeat’.
Once a human is infected, the virus can then spread from person-to-person via contact with the blood or other bodily fluids of a sick or dead person, or via contact with contaminated objects such as needles and syringes and unsterilized medical instruments.
Ebola is not known to spread through the air or by water.
The virus has been found in blood, saliva, vomit, faeces, urine, semen, tears, and nasal secretions of infected people.
The virus in the blood and other bodily fluids infects another person through broken skin or mucous membranes, such as the mouth, eyes or nose.
Traditional burial ceremonies conducted in affected areas of Africa are a high-risk activity for transmission because the virus can survive in bodily fluids of the deceased for several days.
Signs and symptoms
Humans are not thought to be infectious to other people until they develop symptoms.
Symptoms of EVD begin between 2 to 21 days (average 8 to 10 days) after exposure to the virus. Initially, symptoms may be difficult to distinguish from other more common infectious diseases that occur in Africa such as malaria, typhoid fever and meningitis.
The first symptoms typically include fever, severe headache, muscle and joint aches and weakness.
This is followed by sore throat, vomiting, diarrhoea, stomach pain and rash and in some cases by internal and external bleeding progressing to multi-organ failure and death.
Between 50 and 90 per cent of EVD cases in Africa die of the disease.
Who is at risk?
People who live in, or travel to, affected areas of Africa may be at risk of exposure to Ebolavirus. However, the risk of infection is extremely low unless there has been direct contact with the bodily fluids of an infected person or animal, whether alive or dead.
Carers of ill relatives and healthcare workers who are in contact with infected people are at risk of infection, particularly those in resource-poor settings where there may be limited access to hand-washing facilities and protective equipment. Protective clothing and equipment (including masks, gloves, gowns and goggles) should be worn when caring for a sick person.
How is it prevented?
There is currently no vaccine to prevent EVD.
The best prevention is to avoid close contact with infected animals and people, including bodies of the deceased.
Hunting and contact with ‘bushmeat’ in affected areas of Africa should be avoided.
Where contact with people with suspected or confirmed Ebolavirus infection is necessary – usually only in a specialist healthcare facility – recommended infection control procedures, including meticulous attention to hygiene and use of appropriate personal protective equipment, is necessary.
How is it diagnosed?
EVD is confirmed by a test on blood or other body fluids. Testing for EVD is only performed at designated laboratories with special biosafety facilities.
How is it treated?
There are currently no specific treatments available for patients with EVD, although new experimental vaccines and drug therapies are being developed some experimental treatments are being tested. Early diagnosis and prompt supportive therapy, such as intravenous fluid replacement, can be life-saving.
What is Western Australia’s public health response?
There are national and state plans and guidelines for identification, investigation and management of suspected or confirmed cases of EVD, should the disease be imported into Australia.
Public health measures include:
- Screening procedures at international air and sea entry ports to identify arrivals from countries experiencing outbreaks of EVD. These people are assessed for their risk of EVD and accordingly their health may then be monitored on a daily basis by public health officials.
- Doctors and laboratories are required to immediately report any suspected or confirmed EVD cases to the Department of Health.
- Suspected cases of EVD are referred to designated hospitals for testing and management in special isolation facilities.
- WA hospitals have procedures in place to identify suspected cases or EVD promptly and to ensure suspected cases are appropriately isolated, tested and managed to minimise the risk of transmission to other patients or hospital staff.
- Contacts of an infected person will be identified by public health officials and given information about the risk of infection and then monitored for development of symptoms suggestive of EVD. Should this occur, they will immediately be referred for isolation, testing and clinical management.
Information current as of Friday 17 July 2015
- Ebolavirus disease, often called Ebola, is a serious and often fatal disease caused by Ebolavirus.
- People who are living in or travelling to affected areas of Africa may be at risk of infection.
- It is diagnosed by a blood test that detects the virus in blood.
This publication is provided for education and information purposes only. It is not a substitute for professional medical care. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your healthcare professional. Readers should note that over time currency and completeness of the information may change. All users should seek advice from a qualified healthcare professional for a diagnosis and answers to their medical questions.