That number could skyrocket many years from now, they said, if the BSE/variant CJD pathologic prion protein form behaves similarly to the kuru prion protein. On the other hand, many potential vCJD patients may die of competing diseases over the intervening decades during the prion protein incubation.
"The eventual size of the vCJD epidemic remains uncertain," wrote The Lancet editors in an accompanying commentary.
"The number of infected individuals is still unknown," they added. "By investigating kuru, the only known example of a major human epidemic of a prion disease, we will begin to narrow our present uncertainties about vCJD. Any belief that vCJD incidence has peaked and that we are through the worst of this sinister disease must now be treated with extreme skepticism."
Dr. Collinge and colleagues studied people of the South Fore linguistic group from the eastern highlands of Papua New Guinea. Up until the middle of the 20th century, when the practice was stopped by Australian authorities who controlled the island, the South Fore typically ate the brains of relatives at funeral feasts as a sign of respect and mourning.