February 3, 2011

Blood Test For Human Mad Cow Disease Developed

Researchers have developed what is being called "the world's first accurate blood test" for the human form of mad cow disease, and their discovery could change the way the illness is screened for and diagnosed, the UK-based Medical Research Council (MRC) announced Thursday.

According to an MRC press release, the prototype test proved 100,000 times more sensitive than any previous method used to detect variant Creutzfeldt-Jakob disease (vCJD)--a potentially fatal disease that attacks the brain and is believed to have been passed to humans from cattle through infected food products--in an early trial.

The researchers tested 190 blood samples searching for prions, a type of infectious protein that is known to cause vCJD. Twenty one of the blood samples were known to be infected, and according to the MRC press release, the blood test was successfully able "to detect blood spiked with a dilution of vCJD to within one part per ten billion."

This research, which has been published in the British medical journal The Lancet, could mark the first step towards developing an accurate blood test for the disease. Such a test "would enable people to be diagnosed earlier and could also help identify carriers of the disease," which has been known to lay dormant and undetected in a person's system for up to five decades.

"This test comes at the end of many years of meticulous, painstaking research," Dr. Graham Jackson, lead author of the study and the director of the MRC's Prion Unit, said in a statement.

"Although further larger studies are needed to confirm its effectiveness, it's the best hope yet of a successful early diagnostic test for the disease," he added. "This test could potentially go on to allow blood services to screen the population for vCJD infection, assess how many people in the UK are silent carriers and prevent onward transmission of the disease."

According to Bloomberg's Eva von Schaper, vCJD was first linked to bovine spongiform encephalopathy, the prion disease better known as mad cow disease, in 1995. Symptoms of the disease, which can be contracted by eating tainted meat or through blood and/or plasma transfusions, include personality change and impaired memory and thinking stills, notes von Schaper.

"World Health Organization data, which only go up to 2002, show that from October 1996 to November 2002, 129 cases of vCJD had been reported in Britain, six in France and one each in Canada, Ireland, Italy and the United States," adds Kate Kelland of Reuters. "Experts say the disease affects about one person in every million per year worldwide."


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