February 2, 2009

 

North American and German researchers announced a breakthrough on Friday (Jan 30) toward a cheap, fast blood test for bovine spongiform encephalopathy (BSE) in livestock.

 

The research paves the way for a simple blood test to eliminate infected animals from the human food chain, even before the onset of clinical signs.

 

University of Calgary principal investigator, Christoph Sensen said currently the only way to accurately test for BSE, and for similar wasting diseases that affect cattle, is to dissect each animal's brain after slaughter.

 

Sensen said that more tests are needed, but predicted that slaughterhouses will conduct routine tests on all animals to rule out the disease within a few years.

 

He said each two-dollar test could potentially cover 10 animals and take about two hours.

 

He added that it could be done easily by veterinarians in slaughterhouses as animals go in, as part of the pipeline that processes beef.

 

He explained that scientists infected elk and cattle by feeding them several grams of infected brain material where rate of both infection and fatality was 100 percent. Scientists drew blood from each animal monthly and tested circulating nucleic acids.

 

Months before the infected animals showed the first visible symptoms of disease, scientists detected patterns in the blood – genetic material unique to diseased animals, and not found in healthy animals.

 

The genetic changes were caused by the creature's responses at a molecular level to the stress of the infection.

 

He noted that full testing of the cattle infected with BSE will take longer than tests on elk, partly because cattle take longer to die, adding that the researchers are also developing tests for bison, sheep and other species.

 

Infections have been periodically detected in cattle throughout much of Europe and North America, leading to global import bans from affected countries and mass slaughters, including about 4.4 million animals killed during a 1990's outbreak in Britain.