Rabies and Australian bat lyssavirus
Australian bat lyssavirus (ABLV) is a virus carried by bats. ABLV can be transmitted from bats to humans, livestock, horses and pets, causing serious illness with progressive neurological signs. The virus was first identified in 1996 and has been found in both, flying foxes or fruit bats (macrobats) and insect-eating microbat species, so we assume that all bat species in Australia have the potential to carry the virus.
ABLV is more likely to be found in injured or sick bats. Signs of ill-health such as unusual or aggressive behaviour, or other neurological signs such as paralysis or seizures can be suggestive of ABLV infection, however bats that appear healthy may also carry the virus.
Although ABLV is rare, you should treat all bats as if they could be carrying ABLV. Avoid handling bats unless you have been vaccinated against rabies, are wearing appropriate personal protective equipment (such as gloves, face mask or eye protection) and are familiar with handling bats.
ABLV is closely related to classical rabies virus, which causes serious and usually fatal disease in humans, livestock, horses and pets in many countries around the world.
Australia is free of rabies virus.
Research suggests that infection with ABLV is rare. It is estimated that less than 1 per cent of wild bats carry the virus, although in sick or dead bats presented to the laboratory for testing the prevalence is higher.
As of January 2020, 3 people have died in Australia from ABLV infection. All three cases had a history of bites or scratches from an infected bat and none of the affected persons had previously been vaccinated against rabies.
The only reported cases of ABLV in domestic animals in Australia have been associated with two yearling horses in Queensland (May 2013). The horses had been grazing together and were believed to have been infected at the same time.
Despite the lack of confirmed animal-related ABLV cases in Australia, there are several overseas reports of other closely related lyssaviruses that have caused disease in a wide range of domesticated and wild-animal species.
There have been no reported cases of ABLV transmission between infected ‘non-bat’ animals and people, however based on evidence from similar viruses it should be assumed that this could be possible.
Is ABLV a risk to people?
ABLV is a zoonotic disease (transmitted from animals to humans) and can cause serious disease in people.
Anyone handling bats or other potentially infected animals or materials must have a current rabies vaccination and use protective gear.
Classical rabies virus is closely related to ABLV and the rabies vaccine is believed to provide cross-protection.
Veterinarians, nurses and wildlife carers who regularly handle bats or flying foxes are at risk of becoming infected with ABLV and should consider pre-exposure vaccination with the rabies vaccine. Regular rabies titre checks, (blood tests) are recommended to determine if a booster rabies vaccine is required. Seek medical advice for current human health recommendations.
The general public and non-rabies vaccinated individuals should be discouraged from rescuing or handling bats. Trained wildlife carers or Department Environment, Land, Water and Planning (DELWP) wildlife officers can be contacted to provide a safe and effective means of assisting dead or injured bats.
Anyone handling bats should always use Personal Protective Equipment (PPE) even if the bats appear healthy. It’s important to protect yourself from scratches and bites to minimise the risk of infection.
Recommended PPE includes:
- two layers of gloves are worn — outer gloves that are puncture resistant Hexarmor® or leather handling gloves that meet relevant Australian Standards (e.g. AS 2161.3 Occupational protective gloves. Protection against mechanical risks) and a nitrile or latex under-glove
- long sleeves and pants of heavy material
- P2 facemask (minimum) or face shield
- protective eyewear.
The use of puncture-resistant gauntlets to protect the forearms are also recommended.
Do not allow bats of any age, regardless if they appear healthy or sick, to be handled or touched by children or other people who do not have a current rabies vaccination.
I have been been bitten or scratched by a bat
Anyone who has been bitten or scratched by a bat must immediately contact their local medical practitioner or the Department Health and Human Services Communicable Disease Unit on 1300 651 160.
Immediately wash the affected area with soap and water and apply an antiseptic such as iodine-based solutions or alcohol (ethanol).
The Department of Health and Human Services (DHHS) fact sheet, 'Australian bat lyssavirus (ABLV)' is also available at Better Health Channel Victoria
I think my pet (or other animal) has come into contact
If you find your pet or horse in contact with a bat (or suspect this has happened) or if your animal is showing signs suggestive of ABLV infection, immediately report the incident to the Emergency Animal Disease Watch Hotline on 1800 675 888, your local Agriculture Victoria Animal Health and Welfare staff or to your private veterinarian.
ABLV is a notifiable exotic disease and must be reported immediately under the Victorian Livestock Disease Control Act.
Transmission of the virus
The virus can be transmitted from bats to humans, livestock, horses or pets when infected bat saliva enters the body, usually through a bite or scratch. Other risks include bat saliva exposed to the eyes, nose or mouth through aerosol droplets, or into a pre-existing break in the skin (such as a cut or wound).
ABLV is unlikely to survive outside the bat or in a dead bat for more than a few hours, especially in dry environments that are exposed to sunlight. Contact with bat faeces, urine or blood do not pose a risk of exposure to ABLV, nor do living, playing or walking near bat roosting areas.
The time from exposure to the virus, to the start of symptoms varies — from several weeks to years. So it is vital to seek medical advice for exposed people or veterinary advice in cases of livestock, horses or pets even if some time has elapsed since the exposure.
Clinical signs in infected bats are variable, ranging from clinically normal to severe neurological disease. Clinical signs may include:
- bats in unusual locations during the daytime (not in normal roosts)
- bats on the ground or low in a tree with an inability to take off or fly normally or appear to be injured
- behavioural signs (such as aggression, docility, shivering and salivation)
- respiratory difficulties, change of voice
- seizures, tremors, paralysis or weakness.
Clinical signs in non-bat species are likely to be similar to those of rabies.
Horses that become infected may develop severe nervous signs such as seizures, difficulty in swallowing and movement abnormalities.
Dogs and cats that became infected might develop paralysis of the throat and jaw muscles resulting in foaming at the mouth. Signs may also include:
- staggering caused by paralysis of the hind legs.
All suspected cases of ABLV in injured or sick bats or other animals (such as pet dogs and cats or horses) should be reported to Agriculture Victoria, via the Emergency Animal Disease Watch Hotline on 1800 675 888 and investigated by a veterinarian.
All human exposures must be reported to DHHS or qualified medical practitioners.
Advice for veterinarians can be sourced in the following document:
Management of animals exposed to ABLV (Suspected exposure)
Post-exposure vaccination is recommended for pets and horses, even if the exposure to the infected bat was some time ago (days or weeks).
You should contact your veterinary practitioner who can apply to the Chief Veterinary Officer in Victoria for approval to undertake rabies vaccination of the exposed pets, horses or livestock. This vaccine can only be used under a special permit.
Veterinarians should contact Agriculture Victoria for further information on applying for a rabies vaccine.