Deer muscle a source of infectious prions

NEW YORK (Reuters Health) - Findings from an animal study suggest that disease-cause prions can be spread via infected skeletal muscle from deer with chronic wasting disease (CWD) -- a wildlife illness related to mad cow disease.

Whether CWD can be passed to humans is still unclear, but the present findings suggest that if this does occur, simply handling the meat of infected dear could pose a risk, senior author Dr. Glenn C. Telling, from the University of Kentucky in Lexington, and colleagues warn in the journal Science.

The researchers injected muscle or brain extracts from CWD-affected mule deer into the brains of mice.

As expected, the brain extracts were much more efficient at causing disease in the mice. Still, all of the muscle extracts caused progressive neurologic dysfunction too, albeit with longer incubation times.

These results show that muscle, "which is likely to be consumed by humans, is a significant source of prion infectivity," the authors write. "Humans consuming or handling meat from CWD-infected deer are therefore at risk to prion exposure."

SOURCE: Science January 26, 2006.