NPR's "The Salt" [npr.org] column carries the grusome (but interesting) story of a medical mystery:
When researchers made their way to the highlands of Papua New Guinea in the 1950s, they found something disturbing. Among a tribe of about 11,000 people called the Fore, up to 200 people a year had been dying of an inexplicable illness. They called the disease kuru, which means "shivering" or "trembling."
Once symptoms set in, it was a swift demise. First, they'd have trouble walking, a sign that they were about to lose control over their limbs. They'd also lose control over their emotions, which is why people called it the "laughing death." Within a year, they couldn't get up off the floor, feed themselves or control their bodily functions.
Shirley Lindenbaum, a medical anthropologist with the City University of New York, who continues to write about the epidemic, knew it couldn't be genetic, because it affected women and children in the same social groups, but not in the same genetic groups. She also knew that it had started in villages in the north around the turn of the century, and then moved south over the decades.
...
Lindenbaum had a hunch about what was going on: In many villages, when a person died, they would be cooked and consumed. It was an act of love and grief. ... Women removed the brain, mixed it with ferns, and cooked it in tubes of bamboo. They fire-roasted and ate everything except the gall bladder. It was primarily adult women who did so, says Lindenbaum, because their bodies were thought to be capable of housing and taming the dangerous spirit that would accompany a dead body.
Finally, after urging from researchers like Lindenbaum, biologists came around to the idea that the strange disease stemmed from eating dead people.
The story goes on to explain that the disease wasn't spread by avirus or a bacterium, fungus, or parasite. It could survive being boiled into soup, and had no DNA. It was a totally new infectious agent.
It was a twisted protein called "prions," or "proteinaceous infectious particles", that could cause normal proteins in nerve cells to twist just like them, and slowly over long periods of time kill areas of nerve cells in the brain.
The story goes on to cover the similarity to Mad Cow Disease [wikipedia.org], a species jumping disease also caused by prions, and Chronic Wasting Disease [cdc.gov] that is affecting mule deer, white-tailed deer, elk, and moose in 21 states.
The CDC is working with public health authorities in Wyoming and Colorado to monitor hunters for signs of prion disease.
If the Zika doesn't get us, the Kuru probably will.