Tuesday, November 9, 2010
Cairns Vet warns of virus risks from sick bats
Cairns Vets receive many calls about sick and injured wildlife, and treat hundreds of cases of injured wildlife annually. Where the unwell animal is a bat or flying fox, however, we always refer these calls to Wildlife services such as FNQ wildlife rescue or the Tolga Bat Hospital. Cairns Vet Clinic does not accept or examine any species of bat, and the same is true for most Cairns Vets, unless all their staff are vaccinated against Rabies virus.
The reason for this is that bats carry a number of zoonotic diseases (which means animal infections which can cause illness in humans). Over 40 viruses have been isolated from bats over the last 4 decades. Several of these can cause serious human illness, including Australian Bat Lyssavirus, Hendravirus, Nipah Virus, Menangle virus and Rabies virus.In particular, the Australian Bat Lyssavirus can cause a fatal encephalitis in people.
Australian Bat Lyssavirus (ABLV) is a rabies like illness which infects many species of flying foxes and microbats. While the infection is rare (less than 1%) in healthy bats of most species, up to 5-10% of sick bats tested may be infected. Symptoms include weakness, paralysis, seizures, mouth problems such as licking or difficulty swallowing. Some bats may be angry or aggressive toward people (which is unusual in bats).
Bats are an important part of the Australian ecosystem and increasing development and destruction of habitat has brought them into close contact with human settlements. For example, Cairns Vet Clinic at 76 Pease St, Manunda has a large colony in a reserve in the back yard.
The recent Cairns Post Article on deformed bats brought attention to an interesting area of wildlife disease in our area. One of our roles as vets is to advise the public of community health issues, especially where they relate to zoonotic disease. Australian Bat Lyssavirus is recognised as a serious problem by Australian Vets and Government authorities, and there is a AustVet Plan disease strategy for dealing with it.
Any bat which is ill or injured should be treated as a suspect case of Lyssavirus and only handled by experienced bat handlers who have had Rabies vaccination.
There is limited knowledge is known about flying fox diseases, and further research will be required to identify the cause of the deformities seen in Cairns and also on the tablelands. In other animal species, deformities may be caused by viral infections (such as Akabane virus in cattle which can cause twisted limbs and cleft palates) and toxicities (eg. Nicotiana spp. and Solanum Spp. cause birth defects including cleft palates in various species: Flying foxes are known to feed on the related Solanum mauritianum [Wild tobacco] and seasonal variations in availability and toxin levels could result in variability in cases of toxicity). Birth defects like cleft palates often occur when there is some toxic or infectious insult to the fetus at a critical stage of development. In many cases, younger fetuses may be more severely affected and undergo abortion or severe neurological problems. As the fetus matures it is less vulnerable to the pathogen.
If you are bitten or scratched by a bat or come into contact with a sick bat, you should immediately wash the affected area in a virucidal wash such as betadine scrub, and seek immediate medical attention. You may need Rabies vaccination and immunoglobulin. Without this prophylaxis, Rabies and Australian Bat Lyssavirus are almost always fatal and can take weeks or months to develop.
Bats and other wildlife can also carry other zoonotic diseases, so you should not handle these animals unless you have the right training and knowledge. If you do handle wildlife or other animals be sure to wash your hands thoroughly.
Read the original article on Mystery of the mutant baby bats
Read the Cairns Post follow up story including Virus fears in mutant bats in Cairns
Read the Courier mail stub on Vet fears virus is causing deformed bats with cleft palates and twisted limbs in Cairns