Download An Update on Devil Facial Tumour Disease in Tasmanian Devils

AN UPDATE ON DEVIL FACIAL TUMOUR DISEASE IN TASMANIAN DEVILS
Alexandre Kreiss
Menzies Research Institute Tasmania
The Tasmanian devil (Sarcophilus harrisii), the world’s largest marsupial carnivore endemic to
Tasmania, is facing extinction due to an emergent transmissible cancer, devil facial tumour disease
(DFTD). This disease is clearly an important problem and devils have been recently upgraded to
‘endangered’ under the Tasmanian and Commonwealth of Australia listings.
The disease was first recognised in the far north east of Tasmania, in 1996. Since then, it has spread
south and west and now affects devils in over 60% of the island. The disease affects predominantly
animals of breeding age and older, therefore, a complete crash in the adult population is observed
soon after DFTD arrival (Hawkins et al. 2006). Juvenile breeding (and therefore DFTD infection) has
been observed in areas where adult devils are absent due to the tumour (Jones et al. 2008).
DFTD is one of only two transmissible cancers in existence, the other being the canine transmissible
venereal tumour. DFTD is transmitted during biting and these tumours are not rejected by the host
immune system, despite being a ‘cell allograft’ (Pearse and Swift 2006; Siddle et al. 2007; Murchison
et al. 2010). DFTD tumour cells are of Schwann cell origin and are found predominantly on the face
and mouth tissues. Metastasis to distant organs, such as lung, kidney and local lymph nodes are
common. Affected devils die of starvation, secondary infection in the tumour or due to metastasis to
vital organs, usually six to 12 months after the tumour is first visible (Hawkins et al. 2006; Loh et al.
2006). Many aspects of the disease are still unknown (such as the mechanism of tumour acceptance
and the incubation period), but it is likely that most transmission occurs during the breeding season,
when animals have a greater contact with each other. No resistance has been found in the wild and
the only current management strategy to protect the species is the establishment of insurance
populations. Without a cure or prevention, the species faces extinction in 20-30 years (McCallum et
al. 2007).
Suggested reading:
Pearse AM, Swift K (2006) Allograft theory: transmission of devil facial-tumour disease. Nature
439: 549.
Hawkins CE, Baars C, Hesterman H, Hocking GJ, Jones ME, et al. (2006) Emerging disease and
population decline of an island endemic, the Tasmanian devil Sarcophilus harrisii. Biological
Conservation 131: 307-324.
Murchison EP, Tovar C, Hsu A, Bender HS, Kheradpour P, et al. (2010) The Tasmanian devil
transcriptome reveals Schwann cell origins of a clonally transmissible cancer. Science 327:
84-87.
Loh R, Bergfeld J, Hayes D, O'Hara A, Pyecroft S, et al. (2006) The pathology of devil facial
tumor disease (DFTD) in Tasmanian devils (Sarcophilus harrisii). Vet Path 43: 890-895.
Tovar C, Obendorf D, Murchison EP, Papenfuss AT, Kreiss A, et al. (2011) Tumor-Specific
Diagnostic Marker for Transmissible Facial Tumors of Tasmanian Devils:
Immunohistochemistry Studies. Vet Pathol 48(6): 1195-203.
Kreiss A, Cheng Y, Kimble F, Wells B, Donovan S, et al. (2011). Allorecognition in the
Tasmanian Devil (Sarcophilus harrisii), an Endangered Marsupial Species with Limited Genetic
Diversity. PLoS One 6(7): e22402.