 |
|
|
 |
Are bats getting a bad rap? |
|
 |
 |
 |
 |
|
SARS horseshoe bat Rhinolophus macrotis
Picture by Tigga Kingston, Texas Tech University.
|
|
 |
|
BATS, long feared for their mythical associations with vampires, have a new image to overcome, that of reservoirs for viruses potentially fatal to humans.
Scientists at the Australian BioSecurity CRC have been investigating the role bats have in spreading zoonotic viruses (those transmitted from animals to humans).
Bats have been identified as natural hosts to diseases such as severe acute respiratory syndrome (SARS), Hendra virus, Nipah virus, Ebola virus, Menangle virus and Australian bat lyssavirus ( a virus related to rabies).
To date four Australians have died as a result of viruses known to be carried by bats. Two have died of Hendra virus and two of bat lyssavirus.
Australia has around 90 species of bat. Unlike many other mammals bats have the ability to cross borders and natural barriers such as oceans with some species flying up to 50 kilometres in a single night and other nomadic species travelling 2000km in a year.
This unique ability means that bats have the potential to introduce a range of viruses into Australia undeterred by the nation's strict border security or natural island status.
In 2005, bats were identified as the likely host of the SARS virus, a virus that has killed more than 770 people worldwide, most of these in Asia.
Bats can shed viruses through biting or scratching another animal; through their saliva on fruit droppings; or via urine.
It is thought that the Hendra virus was transmitted to horses from bats via fruit dropped by infected bats in Queensland. The first outbreak of the virus, near Brisbane, killed 13 horses and their trainer in 1999.
There have since been six more outbreaks of the Hendra virus, the most recent in November last year.
Flying foxes common in the North Kimberley are thought to carry Australian bat lyssavirus. Bat lyssavirus rarely infects humans but was responsible for two deaths in Queensland in the 1990s.
The Australian BioSecurity CRC's research has highlighted the danger bats pose to human health but also the creatures' potential to avert a pandemic.
Paradoxically bats while acting as reservoirs for certain viruses often appear unaffected and their lack of immune response may hold the key to unravelling ways to fight off an otherwise unstoppable viral outbreak.
By studying the immune response of bats to viruses such as SARS, scientists may be better able to understand the way the virus operates in its hosts. Such information may help prevent or minimise outbreaks in the future.
A recent case of a bat infected with rabies biting two staff members at a school in the United States has demonstrated the danger bats can pose to human health.
Both staff who had handled the bat, which had been kept as a class pet, needed to be treated with a series of painful injections.
Deputy CEO of the Australian BioSecurity CRC Professor John Mackenzie, who is based in Perth, said care should be taken to avoid contact with bats.
"Like all wildlife you need to treat bats with respect," Professor Mackenzie said.
"If a bat appears to be ill it may carry an infectious agent and you should take precautions to protect yourself from possible infection.
"In the case of bats in Australia, the chance of disease transmission from small bats is low but possible from fruit bats.
"If you work with bats you should be immunised against rabies. If you are bitten by a bat you should seek medical advice within 24 hours."
Jane Hammond
|
|
 |
|
|
 |
|
|
 |
 |
 |
There are over 1000 known species of bats, just about a fourth of all mammal species. Most of these bats would fit in the palm of your hand.
|
 |
 |
|
Many important agricultural plants, like bananas, bread-fruit, mangoes, cashews, dates and figs rely on bats for pollination and seed dispersal.
|
|
|
|
Most bats give birth to only a single pup each year, making them very vulnerable to extinction. They are the slowest reproducing mammals on earth for their size.
|
|
|
This article can be found on ScienceNetwork WA.
|
|
|
 |
|
Get it delivered
Learn how Australia's science in motion makes a difference to daily lives. Sign up today.
|
|
|
 |
|
