Disease turning deer into zombies
A disease that turns deer into zombies is on the march across North America and there are fears it could make the jump to humans.
Chronic wasting disease (CWD) - which is related to bovine spongiform encephalopathy (BSE), also known as mad cow disease - has been tracked across 26 states since outbreaks were first reported almost 20 years ago.
The disease gets its nickname from the symptoms it causes. Around 12 months after an animal is infected, it suffers progressive weight loss (wasting,) listlessness, drooling, lack of awareness, lack of fear and aggression. Eventually the infected animal dies.
The disease is caused by proteins (called prions) that attack the brain and spinal tissue.
Symptoms are eerily similar to mad cow disease and its human equivalent, Creutzfeldt-Jakob disease (CJD), which is incurable and has killed more than 100 ein the UK in the late 1980s-early 1990s.
CWD, which was discovered in 1967, is spread through bodily fluids, either directly or through contamination of soil, food, or water.
There's no treatment or cure for CWD, and it's fatal to animals who become infected.
Experts fear the disease could easily make the leap to humans through infected meat.
"We could be having human transmission occurring today and we wouldn't even know it," Dr Michael Osterholm from the US Centre for Disease Control told UK's Independent newspaper.
"The key issue here is that unlike the mad cow disease, here we see (chronic wasting disease) in the muscle as well, so it's actually much more present in the meat that you're eating. Cooking doesn't do anything to destroy it."
There are hundreds of thousands of people in North America who hunt deer. They are being they should not shoot, handle or eat meat from deer or elk that look sick or are acting strangely.