XDA

There are a number of "diseases" out there which are caused not by infection from germs, like viruses and bacteria, but by the introduction of prions into the bloodstream. The more you know about prions (and we don't know much), the scarier it is. One of these diseases is the infamous "Mad Cow" disease, more accurately known as BSE, Bovine Spongiform Encephalopathy. Another is CWD, Chronic Wasting Disease, which infects the deer and elk in the part of Colorado I like to hunt in. Yet another is Creutzfeldt-Jakob Disease (CJD) or kuru, as it is known in New Guinea, which is passed human to human by consumption of human brain tissue. Nice, huh? And recently there's new variant CJD (vCJD) which they think comes from eating Mad Cow infected bovine neural tissue. Apparently they'll eat anything in Europe.

Now Brit scientists are telling us that the English outbreak of Mad Cow disease might have been the result of the contamination of cow feed with human remains from Asia. That's just great. They pick up human bones and flesh from the banks of the Ganges and it all ends up as cow feed in Britain. Money quote (for me):

Prions, the abnormal proteins that cause CJD and vCJD in humans, BSE in cows and scrapie in sheep, are remarkably resistant to both natural decay and sterilisation procedures.

We don't know how scrapie, BSE and CWD (which are probably the same thing in different animals, just as CJD and vCJD are probably the very same disease just in humans) are passed from animal to animal. We don't know how the prions survive the digestive process or break the brain/blood barrier. We don't even know if burning the diseased tissue destroys the prions or just spreads them around more as ash and smoke precipitates. There is no test for a prion-related disease other than looking at brain tissue harvested after death.

Prions create the problem in the brain by merely having contact with brain tissue. They remind me of Ice-Nine in Cat's Cradle by Kurt Vonnegut. The very molecular shape of the prion touching other brain molecules somehow teaches the brain tissue to shape itself like the prion and then all hell breaks loose. The brain becomes spongelike. Death is inevitable, treatment is non-existent and I'm not sure any form of inoculation is even theoretically possible. To avoid getting any of the alphabet soup diseases caused by prions, you have to stay away from prions which are too small to see.

Told you it was scary.