I have been disappointed at the tone of Biosecurity Queensland’s responses to Dr Greg Richard’s and my questions and ideas regarding flying-foxes and Hendra Virus. The major reason why science progresses is that a scientist’s results are subjected to question and review by their peers before being accepted as fact. It is important with something as controversial as Hendra Virus that proper scientific procedure is followed. To label people as deniers just because they ask questions and want to see evidence based proof, is being very disrespectful to science.
The hurriedly organised tele-conference last Sunday involving bat biologists may have been disappointing for BQ – but that is because there was unreal optimism in wanting us all to agree at short notice that there was a direct transmission route for HeV from flying-foxes to horses. Because the evidence is still circumstantial we wanted to find out what new research made BQ so sure of a direct transmission route. The evidence based research has simply not been published. What has been published is the extensive work by AAHL that showed that HeV could NOT be transmitted directly to horses from flying-foxes. This included testing urine, faeces and saliva in all manners and failed to get the virus to transfer from flying-foxes to horses. BQ now wants the support of bat biologists in stating that there is a direct route from flying-foxes to horses. BQ’s belief is based on other circumstantial evidence, which I admit does does have some very strong points – BUT is has not been evidence base tested and published in an appropriate scientific journal. I get very upset in claims that I am adopting a “can’t proove its bats” mentality. All I am asking for is to show me the scientific evidence. The convicting evidence may appear to be overwhelming to BQ but to a scientist this information just represents all the work that needs to be subjected to evidence based research.
It appears that BQ is now pursuing investigations into the shedding of the virus via urine and faeces and this material is then consumed by horses. Why have they dismissed the AAHL’s publication? It will be interesting to see the results of their recent studies published in an appropriate journal – and to see what the research hypothesis states as well as seeing what controls were used.
I accept that BQ staff have plenty of experience in dealing with the public in matters of animal health, but I cannot agree, nor see the advantage of BQ saying that there is direct transmission of HeV from flying-foxes to horses. Why not admit that at this stage we do not know if HeV is transmitted directly from flying-foxes to horses? If humans only contract HeV after it has been amplified via a horse – the same reasoning could be used to argue that horses will only get HeV after it has been amplified through another host or vector. We need to know if the amount of HeV found in flying-fox urine is sufficient to cause the onset of HeV in horses.
As a flying-fox biologist I am continually asked by horse owners and the media – how is HeV transmitted from a flying-fox to a horse, and how can I protect my horse from getting HeV?
HeV is having a major impact on how the public view flying-foxes. I am very pleased that BQ and the Qld State Government have come out very strongly against the culling of flying-foxes. The role of flying-foxes in moving pollen and seeds around our forests is of almost immeasurable value to the health of forests and subsequently our health and well being – let alone the native hardwood industry. To put it bluntly – the Australian environment can survive without horses, but not without flying-foxes.
I would like to see a public statement saying – “flying-foxes are known carriers of HeV but at this stage we lack the research to know if this is the source of HeV that infects horses”. Much more research needs to be done. If the public is led to believe that flying-foxes are to blame, QED, then the fate of our flying-foxes looks very grim."
Best wishes, Dr Les Hall
Les Hall has lived among bats and immersing himself in finding out everything he could about them has taken him into some very odd places.
Broadcast date: Thursday 15 November 2012
There are almost 1000 different species of bats on earth.
They range from the bumblebee bat from Thailand at 1.5 grams, to the large flying foxes of Australia with wingspans of longer than 1.5 metres.
Bat biologist Les Hall devloped his love of birds from his father, and a boss at the CSIRO later introduced him to the wonder of bats.
Les says he's particularly fond of the horseshoe bat - one of the first he identified.
He's co-authored a book with his long-time colleague Dr Greg Richards: The Natural History of Australian Bats: Working the Night Shift published CSIRO Publishing.