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	va1-sg19016.securesites.net

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DEVIL FACIAL TUMOR DISEASE - AUSTRALIA (TASMANIA) (02)

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Researchers have made a breakthrough in understanding a disease that 

has wiped out more than half the Tasmanian devil population but say 

there is no easy solution for stopping its transmission. They say a 

lack of genetic diversity in the devil population is allowing the 

devil facial tumor disease to spread quickly.



Scientists have discovered that none of the animals are mounting an 

immune system attack on the disease, making it particularly 

devastating. The cancer cells in all infected devils are genetically 

identical, indicating the disease originated from a single animal.



"We propose that this tumor arose in a single individual and has 

spread through the population by biting during fights for food and 

mates," Dr Katherine Belov from Sydney University's School of 

Veterinary Science said. The immune system of the original animal did 

not recognize the tumors as foreign. And because Tasmanian devils are 

all genetically similar, their bodies did not recognize that the 

tumors were foreign cells and attack them.



"This information provides a deeper understanding of the nature of 

the disease and will aid in developing effective disease control 

strategies," Dr Belov said. "Essentially, there are no natural 

barriers to the spread of the disease, so affected individuals must 

be removed from populations to stop disease transmission."



Dr Belov said Tasmanian devils had lost genetic diversity in the most 

important gene region for the immune system, the Major 

Histocompatibility Complex (MHC). The devils all had a similar MHC 

type to the tumor, she said. "What also worries me is that many other 

Kangaroo Island; platypuses on King Island," she said. "Loss of 

genetic diversity in these genes just opens the door for emergency 

and rapid spread of new and old disease."



The research, a collaboration between Sydney University, the 

University of Tasmania, the Tasmanian Department of Primary 

Industries and Water, and the Australian Museum, has been published 

online in the journal Proceedings of the National Academy of Sciences.



The disease emerged in the devil population 10 years ago and has 

spread through eastern Tasmania, threatening the existence of the 

species in the wild. Once the cancer becomes visible and spreads 

internally through the body, the animal usually dies within a few 

months from starvation and the breakdown of body functions. 

Scientists predicted at a devil forum in Hobart earlier this year 

[2007] that the species faced extinction within 10 to 20 years at the 

current rate of decline.





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[This is sad news. The most disturbing part of this article is the 

on the cancer who traps and monitors the animals, says 'If the devils 

are ever going to develop immunity -- and to my mind that is the best 

bet -- by removing creatures you are making it less likely.'"



They are running a pilot program on an isolated peninsula where all 

the diseased devils they capture are killed. There is some evidence 

that this approach is working to protect the overall population, 

because, over time, the average age of the animals they capture has 

become older, suggesting that more animals are avoiding the cancer 

and surviving longer. But the program is expensive, and Hamish 

McCallum, chief scientist of the Devil Facial Tumor Program said his 

team was not yet sure about its effectiveness in stopping the disease.



There is no test to detect the disease in pre-tumorous animals. If 

there is no test for the pre-tumorous animals, then clearly they are 

proposing removing those animals that have visible tumors. This 

moderator has seen no reports indicating the expensive experiment 

they know this is the right thing to do to still save the animal 

population? - Mod.TG]



Devil facial tumor disease - Australia (TAS) 20070218.0616

2006

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Devil facial tumor disease - Australia (TAS)(02) 20061024.3051

Devil facial tumor disease - Australia (TAS) 20060201.0328

Undiagnosed deaths, Tasmanian devils - Australia (TAS) 20060127.0264

2005

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Undiagnosed deaths, Tasmanian devils - Australia (05) 20050603.1551

Undiagnosed deaths, Tasmanian devils - Australia (03) 20050531.1507

Undiagnosed deaths, Tasmanian devils - Australia (03) 20050126.0283

Undiagnosed deaths, Tasmanian devils - Australia (02) 20050123.0247

Undiagnosed deaths, Tasmanian devils - Australia 20050122.0233

2003

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Undiagnosed deaths, Tasmanian devils - Australia (03) 20030814.2026

Undiagnosed deaths, Tasmanian devils - Australia (02) 20030812.1999

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