Devil facial tumour disease
[1][2] The cancer manifests itself as lumps of soft and ulcerating tissue around the mouth, which may invade surrounding organs and metastasise to other parts of the body.
DFTD is most often spread by bites, when teeth come into contact with cancer cells; less important pathways of transmission are ingesting of infected carcasses and sharing of food.
In the two decades since the disease was first spotted, population of Devils (Sarcophilus harrisii) declined by 80% (locally exceeding 90%), as the condition spread through virtually all of Tasmania.
[17] Other modes of transmission may include the ingestion of infected carcasses and the sharing of food, both of which involve an allogeneic transfer of cells between unrelated individuals.
[27] Using deep sequencing technology, the study authors then profiled the tumours' transcriptome, the set of genes that are active in tumours; the transcriptomes closely matched those of Schwann cells, revealing high activity in many of the genes coding for myelin basic protein production.
[32] The existence of multiple strains may complicate attempts to develop a vaccine, and there are reports of concerns that the evolution of the cancer may allow it to spread to related species such as the quoll.
Field monitoring involves trapping devils within a defined area to check for the presence of the disease and determine the number of affected animals.
[42] The decline in devil numbers is also an ecological problem, since its presence in the Tasmanian forest ecosystem is believed to have prevented the establishment of the red fox, with the most recent known organism accidentally being introduced into Tasmania in 1998.
[43][24] Tasmanian devil young may now be more vulnerable to red fox predation, as pups are left alone for long periods of time.
The largest of these efforts is the Devil Ark project in Barrington Tops, New South Wales; an initiative of the Australian Reptile Park.
This project aims to create a set of one thousand genetically representative devils, and is now a major focus of the insurance policy.
[46] The Tasman peninsula is being considered as a possible "clean area" with the single narrow access point controlled by physical barriers.
The Tasmanian Department of Primary Industries and Water is experimenting on culling infected animals with some signs of success.
[49] In early 2010, scientists found some Tasmanian devils, mostly in the north-west of Tasmania, that are genetically different enough for their bodies to recognise the cancer as foreign.
[51] In 1996, a photographer from The Netherlands captured several images of devils with facial tumours near Mount William in Tasmania's northeast.
[54] Menna Jones first encountered the disease in 1999 near Little Swanport, in 2001 capturing three devils with facial tumours on the Freycinet Peninsula.
[59] Initially, it was suspected that devils had low genetic diversity, so that their immune system did not recognise the tumour cells as foreign.
[29] However, it was later demonstrated that devils are sufficiently genetically diverse to mount a strong immune response to foreign tissue.
She wounded a male and by October both devils had DFTD, which was subsequently spread to two others (an incident that in retrospect would be understood in the context of the allograft theory of transmission).
[69] In 2006, DFTD was classed a List B notifiable disease under the Government of Tasmania's Animal Health Act 1995.
That is, the individuals with particular forms of these genes (alleles) survived and reproduced disproportionately to those that lacked the specific variants when disease was present.
The tumours were removed,[76] and officials thought Cedric was recovering well, but in September 2010, the cancer was discovered to have spread to the lungs, leading to his euthanasia.
[80] Field testing of the potential vaccines has been undertaken as a collaborative project between the Menzies Institute for Medical Research and the Save the Tasmanian Devil Program.
[82] Research by Professor Greg Woods from the University of Tasmania's Menzies Institute for Medical Research has shown encouraging evidence for the potential development of a vaccine using dead devil facial tumour disease cells to trigger an immune response in healthy devils.
[83] In March 2017, scientists at the University of Tasmania presented an apparent first report of having successfully treated Tasmanian devils with the disease.
Live cancer cells that were treated with IFN-γ to restore MHC-I expression, were injected into the infected devils to stimulate their immune system to recognise and fight the disease.
