Well that's kinda gross:
Kuru killed thousands of Fore beginning in the 1920's and only began to fade after the Australian authorities in the 1950's outlawed the Fore practice of honoring their dead by butchering them with bamboo knives at mortuary feasts, eating them and — by some accounts — smearing themselves with brain tissue, which would drive infection into cuts and scratches.
Hoo boy. Context here is a new medical study noticing that prion disease could incubate in the Kuru for decades before manifestation, thus increasing the likelihood that we've not yet neared the final tally of fatalities from the mad cow outbreak of the 80's. Other scientists disagree. As for me? I'll pass on a burger for lunch. No human brain, either.