Like other wild animals, some bats may carry viruses that can be transmitted to humans. The two major viruses that have been identified in some bats includes the Australian Bat Lyssavirus and the Hendra Virus.
Australian Bat Lyssavirus
Australian Bat Lyssavirus (ABLV) is a rabies-like virus that has been identified in bats. Research to date has shown the virus to be present in four species of flying-fox in Australia, and in three species of micro-bat. Given the fatal consequences of human infection with Lyssaviruses, we need to assume that any and all Australian bats have the potential to carry Australian Bat Lyssavirus at any age, whether they are sick or well.
Only three human cases have ever been documented in Australia, all of them fatal. Infection is thought to occur by a penetrating scratch or bite. The virus is transmitted when an infected bat’s saliva comes into direct contact with exposed human tissue. There is no evidence to suggest that the following pose a risk of infection:
- contact with bat urine or faeces
- bats flying overhead
- bats feeding or roosting in trees
- bats that have been dead for more than four hours
ABLV is not known to be spread by ingestion. However, as a general hygiene measure, fruit that has been damaged by any animal should not be eaten, and fruit which has been soiled should be washed and peeled before being eaten.
The risk of people contracting Hendra Virus (Equine morbillivirus) is extremely low, though the serious consequences of contracting Hendra cannot be over-emphasised, with approximately 80% of horses and 70% of people infected with Hendra virus dying.
Horses contract the virus by ingesting the saliva of infected flying-foxes via eating partially-eaten food. Humans contract the virus from coming into contact with saliva from infected horses.
There is no evidence that humans can catch the virus directly from flying-foxes. Attempting to move a flying-fox colony could increase the stress in flying-foxes and make them more susceptible to carrying the Hendra virus.
If you are bitten or scratched
The known risk of Lyssavirus infection relates to being bitten or scratched by an infected bat. The best approach is to leave bats alone. If you find a sick or injured bat or encounter a bat caught on a barbed-wire fence, do not touch the bat. Contact a local Vet for details on your nearest wildlife carer.
However, if you are bitten or scratched, wash the wound carefully with soap and water for ten minutes. Do not scrub the wound, but do wash it thoroughly. Proper cleansing of the wound is the single most effective measure for reducing transmission of Lyssavirus. Contact your doctor (even if you are already vaccinated) who will contact the local Public Health Unit to arrange appropriate treatment that may include vaccination. If you get bat blood or saliva in your eyes, nose or mouth, you should flush the area thoroughly with water and seek immediate medical advice.
In addition, as with any animal bite or scratch, you should check your tetanus vaccination status to see if you need a booster.
Under Queensland legislation, if you suspect
… an animal is clinically ill with ABLV,
… an animal has been bitten or scratched by a bat or other animal known to be infected with ABLV,
… the presence of Hendra Virus in any species of animal,
you must report it to Biosecurity Queensland on 13 25 23 or contact the Emergency Disease Watch Hotline on 1800 675 888.
Flying-foxes have a very efficient digestive system with food passing through the gut in 12-34 minutes. This is to enable them to remain light so that they can easily fly. This means they often defecate in flight, splattering objects beneath their flight path with excrement.
Flying-fox faeces is easily removed with water and does not pose a serious health hazard. The only health hazard from faeces is related to bacteria (e.g. salmonella) which can be found in any animal’s faeces, including humans.
If you come across any fruit or vegetables that have a “splattering” of flying-fox faeces, or from any other animals, you should either wash and peel the item or discard it in the bin.
In swimming pools, faeces is neutralised by normal chlorination. To avoid damage to lacquered surfaces, cars should be covered or parked under cover. To avoid the contamination of rainwater tanks with faeces from any animals, keep water tanks covered, chlorinate regularly and drain and clean the tank and area used for water collection on a regular basis.