What are rabies and Australian bat lyssavirus?
Rabies virus and Australian bat lyssavirus (ABLV) belong to a group of viruses called lyssaviruses. These viruses are usually transmitted via a bite from an infected (“rabid”) animal. They all cause a similar illness known as rabies, which affects the central nervous system and is usually fatal. The World Health Organization estimates that more than 55,000 people die from rabies worldwide each year. Rabies virus does not currently occur in land dwelling animals in Australia. However, ABLV, which is closely related but not identical to rabies virus, does occur in Australia, and can be transmitted from bats to humans. Only three cases of human infection with ABLV have been recorded since the virus was first identified in 1996. All three cases were in Queensland and all died as a result of ABLV infection after being bitten or scratched by bats.
What are the symptoms?
Rabies and ABLV infection are thought to cause similar symptoms. The early symptoms are flu-like, including headache, fever and fatigue. The illness progresses rapidly to paralysis, delirium, convulsions and death, usually within a week or two. Rabies cases and the three known human cases of ABLV infection have shown a wide variability in the time it takes for symptoms to appear following exposure to an infected animal (from several days to several years).
How are they spread?
Both rabies and ABLV are spread from infected animals to people through bites or scratches, or by being exposed to infected animals’ saliva through the eyes, nose, mouth or broken skin. Only mammals can be infected. Overseas, dogs are the main transmitter of rabies. Other animals that transmit rabies overseas include bats, monkeys, foxes, cats, raccoons, skunks, jackals and mongooses.
In Australia, evidence of ABLV infection has been found in species of flying foxes/fruit bats and insect-eating microbats. It is assumed that any bat in Australia could potentially carry ABLV. The behaviour or appearance of a bat is not an accurate guide as to whether it is carrying the virus. The rabies and ABLV viruses are unlikely to survive outside the bat or animal for more than a few hours, especially in dry environments that are exposed to sunlight. Contact or exposures to bat faeces, urine or blood do not pose a risk of exposure to ABLV, nor do living, playing or walking near bat roosting areas, as long as bats are not handled. Apart from two horses, no wild or domestic animals in Australia have ever been found to be infected with ABL.
Who is at risk?
People who handle bats in Australia are at risk of ABLV infection. People who come into contact with wild or domestic mammals, including bats, in a rabies endemic country are at increased risk of rabies infection.
How is it prevented?
The best protection against being exposed to rabies or other lyssaviruses (including ABLV) is to avoid handling any bat in Australia or overseas, or any wild or domestic land dwelling mammal in a country where there is a rabies virus risk. This includes bats and wild or domestic dogs, cats and monkeys. Only people who have been vaccinated against rabies and who have been trained in handling bats should ever handle bats or flying foxes. Anyone who comes across an injured bat should contact the local Wildlife Information Rescue and Education Service (WIRES) network on 1300 094 737. WIRES have trained staff who can deal with bats safely. A private veterinarian may also be able to offer assistance and advice. Do not touch the bat and avoid direct contact with any bat saliva.
Rabies vaccine is used to protect against rabies and ABLV infection before a potential exposure. A course of three injections, given over one month, is recommended for people whose job or other activities place them at increased risk of being bitten or scratched by bats in Australia or mammals in rabies endemic countries. Periodic booster doses of vaccine may also be required. Rabies vaccination may also be recommended for people who travel to a rabies endemic country, depending on the circumstances (see the Rabies Information Sheet for Travellers for further information).
Rabies infection may also be prevented following an exposure through proper wound care and, depending on the outcome of a risk-assessment, by a series of injections known as post-exposure prophylaxis (PEP) or post-exposure treatment (PET) - see the below for advice on what to do if potentially exposed.
What should I do if bitten, scratched or exposed to a potentially rabid animal?
Even if previously vaccinated, if you are bitten or scratched by a bat anywhere or by a land dwelling mammal overseas, you should:
- immediately wash the wound thoroughly with soap and water for at least five minutes - proper cleansing of the wound reduces the risk of infection
- apply an antiseptic with anti-virus action such as povidone-iodine, iodine tincture, aqueous iodine solution or alcohol (ethanol) after washing
- seek medical attention as soon as possible to care for the wound and to assess whether you are at risk of infection
If you are at risk of infection, you may require treatment consisting of a combination of rabies immunoglobulin and rabies vaccine. If you have not been vaccinated previously, you will require an injection of rabies immunoglobulin as soon as possible and a series of either four or five rabies vaccine injections over one month. If you have been vaccinated before with a full course of vaccination, you will require two further doses of vaccine. In NSW, Public Health Units will work with your doctor to assess your risk and where indicated, will arrange for rabies vaccines and immunoglobulin to be delivered to your GP or hospital.
If exposure occurs while abroad, wherever possible, you should seek treatment as soon as possible in that country. Rabies immunoglobulin may be difficult to obtain in some countries but vaccine is usually available. If you do receive treatment while abroad, you should ask for a post-exposure prophylaxis (PEP) certificate, and as much written details about treatments received as possible, preferably in English (see the Rabies Information Sheet for Travellers for details).
If the animal or bat can be observed or tested without placing other people at risk, health authorities may decide to delay your treatment for a short period of time. In Australia, testing of bats can be arranged by local public health units. If it is found that the animal is not a rabies risk, the course of vaccinations will not be required and can be ceased.
How is it diagnosed?
Diagnosis of rabies and ABLV can be difficult and confirmation requires laboratory tests for the presence of the virus in skin, blood, spinal fluid and nervous tissue.
How is it treated?
There is no available treatment for rabies or ABLV once symptoms have started.
What is the public health response?
Doctors should contact their local public health unit for advice on people bitten or scratched by animals or bats that could transmit rabies or ABLV. Public health unit staff will help arrange vaccination following exposure and rabies immunoglobulin where required. Hospitals and laboratories will notify cases of rabies and ABLV infection to the local public health unit. Public health unit staff will investigate the likely source and determine whether others may be at risk of infection.
For further information please call your local Public Health Unit on 1300 066 055 or visit the New South Wales Health rabies website.
For further information regarding domestic animals that have been exposed to sick bats, please visit the NSW Department of Primary Industries website