Concocted bat maladies promoted by The Townsville Bulletin

How many ways can those fearsome flying-foxes inflict illness, injury or death on their hapless, helpless Homo sapien victims in Charters Towers? At least three viral diseases, a fungal disease, various blood-sucking insects, faecal contamination and getting in the way of the emergency helicopter is the tally to date based on stories published in the Townsville Bulletin.

Their list of bat maladies and health risks has been growing rapidly, with four new ones added in the past month: (A) histoplasmosis, (B) blood-sucking mites, (C) Melaka virus and (D) lyssavirus spread by the water supply. But there is no evidence to support the existence of any one of these alleged problems in Charters Towers and they are all based solely on the assertions of the town mayor, a federal MP and those claiming to be affected by these mystery ailments. No health experts are cited or quoted to substantiate the allegations, which contradict expert advice and medical information.

(A) Histoplasmosis [1]: Headlined ‘Disease strikes bat-ridden town’, this story was based on a man’s reported belief that his undiagnosed illness of three years was due to the bats: “Charters Towers man Ronald Jenkins believes an epidemic of bat disease, or histoplasmosis, is behind his major health problems and the ill health of many other town residents.” Despite no doctor having made a diagnosis, “Mr Jenkins swears the problem lies squarely with the colony of an estimated 20,000 bats that has infested the town for years.”

There are no records in the medical literature of histoplasmosis caused by flying-fox faeces, and it is most commonly caught from the accumulated droppings, known as guano, from insectivorous, cave-dwelling bats [2], which are very different to the flying-foxes that roost in Charters Towers.

(B) Bood-sucking mites [3]: The Townsville Bulletin has published two stories and an editorial on alleged tick-like mites, with the first claiming that “Charters Towers residents under siege from a colony of bats are also faced with a plague of blood-sucking mites” and the second that a resident had been wounded on an arm by one of the insects: “[Mr Burnham] showed the Townsville Bulletin a scar on his left arm that Mr Burnham said was caused by an insect that latched on to his skin and fed on his blood.”

Again, no health experts or biologists were cited to support the existence of these alleged mites. Flying-foxes are known to host a few species of mite as well as parasitic wingless flies (Nycteribiidae), but there is no record in the medical literature of insects transferring from flying-foxes and taking blood meals from humans. Wildlife carers who have close contact with flying-foxes have not reported problems with blood-sucking insect attacks [4].

Most mites and the Nycteribiid flies are specific to one or several related hosts and cannot parasitise other species [5]. For these insects to transfer from a host to another animal would normally require close contact with the host animal, which should not be occurring in Charters Towers. Mites do not survive long off their hosts [6]. Occasionally, humans catch scabies from animals (more than 40 species are known to host these mites), but the infestation is usually self-limiting and requires contact with the animal (and the scabies mite is not a blood sucker) [7].

(C) Melaka virus [8]: Mentioned as a threat along with lyssavirus and Hendra virus in a quote from the town mayor, this virus is not known to exist in Australia. It has caused a flu-like illness in one Malaysian family [9]. This virus was also falsely promoted as a risk for Charters Towers on an ABC TV news item on 28 November, see our blog post here.

Confusion about the presence of Melaka in Australia may have originated from this article on the ABC website that quotes Australian scientists and is not wholly clear that the infection had occurred just in Malaysia, not in Australia.

(D) Lyssavirus via the water supply [10]: The Townsville Bulletin quoted Federal MP Bob Katter saying about lyssavirus “Now remember I'm not saying it's as simple as it stepping out of a bat and into a human, but the water supply is one way."

Health experts say spread by the water supply is not possible, Queensland Health stating on its website “A bat bite, scratch or mucous membrane exposure to bat saliva is necessary to transmit the virus” [11].

Promoting fear and hypochondria amongst people who live near bats seems to be The Townsville Bulletin’s contribution to the campaign by Charters Towers politicians to get rid of bats from the town (and to get re-elected; the local state MP Shane Knuth has promised residents that within one month of his party coming to power the bats will be gone [12]).

Contrary to the alarmist statements published by The Townsville Bulletin, health authorities advise that living near a bat camp is not a health risk. A brochure published by Queensland Health states, “Flying foxes are not a health risk to you unless you are bitten or scratched” [13]. Of the only virus known, in Australia, to be transmitted by flying-foxes to humans, Australian bat lyssavirus, they say: “There is no known risk of contracting ABL from bats flying overhead, contact with bat urine or faeces or from fruit they may have eaten.  Living, playing or walking near bat roosting areas does not pose a risk of exposure to the virus.” [14]

Queensland Health has sought to reassure Charters Towers’ residents they are not at risk from flying-foxes. In a story carried by Charters Towers’ local paper (the Northern Miner) [15], but not the Townsville Bulletin, Townsville's public health medical officer Dr Steven Donohue was reported as saying that there is “absolutely no evidence” to suggest bats in Charters Towers are carrying human diseases and there had been “no reports of any local residents getting sick from bats”. “Specifically, Townsville Public Health Unit has no record of any cases of histoplasmosis, Hendra virus, Mokola [sic] virus, lyssavirus, mites, lice or any other parasites arising from bats in Charters Towers,” Dr Donohue said.


References:

[1] See http://www.townsvillebulletin.com.au/article/2010/12/01/188675_news.html

[2] O’Sullivan M, Whitby M, Chahoud C, Miller S. 2004. Histoplasmosis in Australia: A report of a case with a review of the literature.  Australian Dental Journal 49(2): 94-97.

[3] See http://www.townsvillebulletin.com.au/article/2010/11/23/186675_hpphoto.html; http://www.townsvillebulletin.com.au/article/2010/11/23/186775_opinion.html; http://www.townsvillebulletin.com.au/article/2010/11/29/188141_news.html

[4] Pinson D. 2007. The Flying Fox Manual. StickeeBatz Publishing.

[5] Walton SF, Currie BJ. 2007. Scabies: diagnostic problems for a global disease in human and animal populations. Clinical Microbiology Reviews 20:268-279.

Bruyndonckx N, Dubey S, Ruedi M, Christie P. 2009. Molecular cophylogenetic relationships between European bats and their ectoparasitic mites (Acari, Spinturnicidae). Molecular Phylogenetics and Evolution 51(2): 227-37.

Hall L, Richards G. 2000. Flying Foxes: Fruit and Blossom Bats of Australia. UNSW Press: University of New South Wales

[6] Mattsson JG, Ljunggren EL, Bergstrom K. 2001. Paramyosin from the parasitic mite Sarcoptes scabiei: cDNA cloning and heterologous expression. Parasitology 122: 555–562.

Bruyndonckx et al. 2009; Walton & Currie 2007. See Note [5].

[7] Mattsson et al. 2001. See Note [6].

[8] See http://www.townsvillebulletin.com.au/article/2010/11/29/188141_news.html

[9] Chua KB, Crameri G, Hyatt A,  et al. 2007. A previously unknown reovirus of bat origin is associated with an acute respiratory disease in humans. Proceedings of the National Academy of Sciences of the United States of America 104(27): 11424-11429.

[10] See http://www.townsvillebulletin.com.au/article/2010/11/29/188141_news.html

[11] See http://www.health.qld.gov.au/goodhealthintnq/topics/abl.asp

[12] See http://www.townsvillebulletin.com.au/article/2009/03/20/45761_news.html

[13] See www.health.qld.gov.au/ph/documents/cdb/livingwithflyingfoxes.pdf

[14] http://www.health.qld.gov.au/goodhealthintnq/topics/abl.asp

[15] Jenkins C. Bats 'no health risk'. Northern Miner. 7 December 2010, page 1.