Nearly 70 percent of the world's Tasmanian devils (Sarcophilus harrisii) have been wiped out in the past 10 years by a contagious cancer known as devil facial tumor disease (DFTD). Now a new test could help determine which devils are carrying the disease before symptoms show up, enabling conservationists to move cancer-free creatures to quarantined areas as they try to save the species from its otherwise likely extinction.
DFTD, which has a six-month incubation period, is a nasty killer. Once it infects a Tasmanian devil, the cancer destroys the animal's mouth, filling it with tumors that make it impossible for the animal to eat. Starvation and death rapidly follow, usually within three to six months of the appearance of physical symptoms. Transmission is easy, since devils frequently bite one another on the mouth during mating or while fighting for territory.
Many scientists have predicted that without aggressive efforts to protect the species from DFTD, Tasmanian devils will become extinct in the wild in as little as 25 years.
Until now, there has been no test to diagnose DFTD before tumors crop up – let alone a cure. This has slowed efforts to establish cancer-free populations and breeding programs. But now scientists at the University of Tasmania report they have developed a preliminary diagnostic test that would reveal which devils carry the cancer in their blood.
The blood tests make use of separation science, which involves the "study of fundamental processes and materials for the separation and subsequent measurement of specific molecules, usually when these are present in very complex mixtures," as defined by the Australian Center for Research on Separation Science at the University of Tasmania.
Robert Shellie, a separation scientist with the university, told The Times of London that he hopes to analyze another 1,000 blood samples over the next six months to validate the diagnostic test.
The test couldn't come soon enough, as DFTD is even showing up in previously disease-free devil populations. A six-year-old female in Trowunna Wildlife Park, Mole Creek, Tasmania,, where DFTD has only been seen once before, was recently found to be infected. For that to have happened, "A wild devil would have to climb over a seven-foot cyclone wire fence...which is probably one of the most secure perimeter fences of the wildlife parks in Tasmania," park owner Androo Kelly told Australia's ABC News.
“Anything that speeds up the detection of the disease," Shellie told The Australian, "has to have a significant impact.”
Images: Healthy and infected Tasmanian devils, via Wikimedia Commons