Richard Rhodes surveys the various spongiform diseases of animals and humans known generically as transmissible spongiform encephalopathy (TSE), summarizing what is known of their histories and causes in DEADLY FEASTS: TRACKING THE SECRETS OF A TERRIFYING NEW PLAGUE.
All of these diseases riddle the brain with holes and are invariably fatal. Kuru is found only in eastern Papua New Guinea, mostly among the Fore people. The disease has stopped spreading with the cessation of cannibalism. A similar TSE called Creutzfeldt-Jacob disease (CJD) occurs apparently spontaneously in one out of one million humans. Both kuru and CJD are transmissible to primates.
Scrapie is an old TSE found in sheep, so-called because of the intense itching that causes the sheep to scrape off their wool. Another form well-known to veterinarians is the encephalopathy that ravages mink farms.
Bovine spongiform encephalopathy broke out in British cattle herds in April, 1985, producing 420 confirmed cases in two years. Controversy followed, with government regulations that many critics found inadequate. Tallying confirmed human victims of BSE is difficult, but Rhodes counts ten cases by early 1996.
Nobody can say for sure what transmits TSE. The evident near-indestructibility of the agent argues against a virus. Biochemist Stanley Prusiner invents the term prion (PREE-on) to suggest an infectious protein particle, allowing for a small nucleic acid possibly harbored inside the particle. Nobel Prize-winning scientist Carleton Gajdusek suspects an abnormal...
(The entire section is 335 words.)