Saturday, December 4, 2010

Even the ABC propagates nonsense about bats

As the public broadcaster, the ABC is required to abide by standards of accuracy, impartiality and balance in its reporting (see the ABC code of practice). But these standards have slipped in some reports filed on flying-foxes, particularly when journalists have yielded to the temptation of sensationalising disease risks.

Flying-foxes carry viruses that can affect humans BUT only one person is recorded as having caught a disease from Australian flying-foxes: a woman died in 1998 from Australian bat lyssavirus after being bitten [1]. Her death could have been prevented by vaccination.

Health departments and health experts advise that mere proximity to bats is not a disease risk (eg. see here) [2]. People just need to take care not to touch bats, and to consult their doctor if they are bitten or scratched (because “bats rarely initiate contact with humans,” this mostly occurs when people try to rescue [3] or harm bats).

But some media reports would have you believe that living near a bat camp is a potential death sentence, including a recent ABC TV news report about a protest in Charters Towers, Queensland, against a bat camp in town (broadcast 28 November, it can be viewed here).

Bat-borne diseases were reported to be the main reason Charters Towers’ residents want the town’s flying-foxes gone, with the newsreader stating that locals say the government is putting their lives at risk by refusing to permit “more proactive measures” to get rid of the bats. Federal MP Bob Katter was shown telling the protesters that “they’ll [the bats? the government?] just laugh at us as we go out there and quite literally die.” The reporter Megan Woodward then referred to three viruses – lyssavirus, Hendra and Melaka – implying that they were all a risk for Charters Towers residents due to the presence of bats: “While links with Hendra and lyssavirus are well-known, the Council says there’s another virus, Melaka, that can be transmitted to humans by bat faeces.”

Not only did the reporter neglect to note that humans don’t catch Hendra virus from bats, and that lyssavirus can’t be transmitted through mere proximity to bats, she concocted a new disease risk that doesn’t even exist in Australia (Melaka virus caused a flu-like illness in a Malaysian family), on the basis of advice from the local government (not normally regarded as health experts). No health expert was interviewed.

The ABC’s failure to research this story properly and the propagation of false information about health risks, with the potential to cause unnecessary alarm in listeners, is irresponsible.

Even an ABC environmental blog managed to inflate disease risks (see here), with reporter Sara Phillips defending Bob Katter’s views on bats and disease: “But Bob Katter isn't mad, you just need to know what he's going on about. Flying foxes do kill people.” [4]

Ms Phillips claimed that flying-foxes have killed six Australians: two from lyssavirus and four from Hendra. But just one death from lyssavirus is attributed to a flying-fox (the one other from a microbat), and flying-foxes do not infect humans with Hendra virus; horses do (but there are no calls for horse culls!) [5].

Flying-foxes are a natural host for Hendra virus. Ironically, people who disperse or kill flying-foxes and destroy their habitat could cause stress-induced spillover events that lead to occasional infections of horses. A scientific review of Hendra and other viruses by Andrew Breed and colleagues [6] warned that the processes driving spillover of infection are those that cause flying-fox decline, including “hunting, roost disturbance and habitat loss or alteration”.

This highlights the importance of reporters properly investigating stories about health threats and consulting experts, to avoid inadvertently supporting the messages of those advocating the very actions likely to increase disease risks.

The ABC news item on the Charters Towers protest was flawed in other ways as well. It implied that the only reason the State Government had refused a permit for helicopter dispersal of the bats was a small risk that bats could be harmed. In fact, human safety was also an issue as flying low over residential areas is considered a hazard by aviation authorities and requires special authorisation, which had not been obtained. Helicopter “mustering” is also likely to fail and result instead in bats moving into residents’ backyards, as has occurred with previous dispersal attempts. Bats are nothing like cattle, and helicopter dispersal didn’t work when it was tried in the Northern Territory.

The ABC news report was also politically biased. It featured three conservative politicians who are each opposed to both bats and the current Queensland Government. The Government was not given a voice in the story (there was one throwaway reference to the environment minister, Kate Jones, at the end of the piece) or the opportunity to respond to false allegations.

Both biased and inaccurate, the reporter stated “With the Bligh Government’s popularity proving to be slipping in polls released today, Charters Towers’ residents are asking Queensland voters to show some solidarity and back their cause and boot the government out.” The reporter had no basis for claiming that “Charters Towers residents” in general want to boot the government out. She could not even legitimately claim that all the protesters want the government booted out unless she had interviewed them all. There are undoubtedly ALP voters in Charters Towers and there are even residents who like having flying-foxes in their park. Unfortunately, bats are being treated as football number one in a nasty political battle, and the ABC seemed to be favouring one side.

The most positive thing that can be said about that ABC news item was that it wasn’t quite as bad as the reporting by the Townsville Bulletin, which has concocted a new blood-sucking creature that jumps from bats to humans in Charters Towers and has sent people to hospital (see here and here).

However, there is usually more to distinguish the ABC from the Townsville Bulletin, as it does regularly feature balanced and informative reporting on flying-foxes. It’s a pity the reporter for the Charters Towers story didn’t at least consult the ABC Online Scribbly Gum site about flying-foxes (see here), which conveys disease risks accurately and states that “just being near a roost will not put you at risk of being infected”.



References:

[1] Hanna J, Carney I, Smith G, et al. 2000. Australian bat lyssavirus infection: a second human case, with a long incubation period. Medical Journal of Australia 172:597-9. Note that the other case of lyssavirus (also fatal) was thought to be due to contact with a microbat. 

[2] For example, a brochure published by Queensland Health explicitly states: “Flying foxes are not a health risk to you unless you are bitten or scratched”. See www.health.qld.gov.au/ph/documents/cdb/livingwithflyingfoxes.pdf.

[3] McCall B, Epstein J, Neill A, et al. 2000. Potential human exposure to Australian bat lyssavirus: Brisbane South and South Coast, Queensland, 1996-1999. Emerging Infectious Diseases 6: 259-264.

[4] It seems strange that an environmental reporter would set out to defend Bob Katter’s views on flying-foxes. Mr Katter characterises flying-foxes in extreme terms as killers and advocates mass culling; contrary to all evidence, he claims they are in “plague” numbers: "There are no varieties that aren't 10 to 100 times the numbers they were at European settlement because back then they had nothing to eat” (see here)

[5] Contrast this with reporting on other diseases. Ross River virus and Barmah Forest virus have been spread to humans by mosquitoes which bit kangaroos and wallabies. The media reports these diseases as being transmitted by mosquitoes, not kangaroos and wallabies. When there is a sequence of hosts, there seems to be a tendency to focus ‘blame’ for the disease on the least popular of them.

[6] Breed A, Field H, Epstein J, Plowright RK, Daszak P. 2006. Emerging henipaviruses and flying foxes conservation and management perspectives. Biological Conservation 131: 211-220.