In 1993, two British dairy farmers died of CJD, a disease that was supposed to strike one out of every 1 million people. The government response was that it was just a bizarre coincidence. In May of the same year, 15-year-old British schoolgirl Victoria Rimmer began having trouble keeping her balance and within weeks she was falling constantly. Admitted to the hospital, Rimmer underwent a battery of tests—all of which came back negative. Finally a brain biopsy was obtained and the doctor who examined the results was stunned. Her brain was riddled with holes and amyloid plaques identical to those seen in the brains of kuru victims. With hesitancy, the physician informed Victoria’s grandmother that the girl had spongiform encephalopathy—mad cow disease. What took place next was even more incredible. An investigator from the government’s CJD-surveillance unit in Edinburgh visited Mrs. Rimmer, warning her not to say anything about her granddaughter’s condition. “Think about the economy,” he told her, “think about the Common Market.”
Victoria Rimmer died in November 1997. After an inquest into her death, coroner John Hughes concluded that she died of natural causes.
In 1994, a 16-year-old schoolgirl and an 18-year-old boy were diagnosed with CJD, which had hardly ever been reported in people less than 30 years of age. By the following year, seven people were already dead or dying.
On March 8, 1996, the hammer fell on the government’s “British Beef is Safe to Eat” stance in the form of a memo written by Dr. Eileen Rubery, a policy maker and longtime government adviser. Rubery confirmed what others had feared for 11 years—the emergence of a new form of spongiform encephalopathy, this one transmitted to humans via the consumption of contaminated beef. She also used the dreaded “e” word: epidemic. The new disease was initially referred to as sporadic CJD or atypical CJD, but scientists eventually settled on Variant Creutzfeldt-Jakob disease (vCJD).
By October 2013, the number of definite and probable deaths from vCJD in the United Kingdom stood at 177. Some researchers see the epidemic as over, pointing to the fact that after peaking in 2000, when 28 people in the UK died of vCJD, deaths from the disease have fallen off dramatically (i.e., three deaths in 2009, three in 2010, and one in 2013). Others believe that these 177 deaths are only the tip of the iceberg. They rationalize that, because thousands of Fore died as adults, sometimes 50 years after being exposed to kuru via ritual cannibalism, many Europeans (and others) who had consumed contaminated beef in the 1970s and 1980s would not have been stricken yet, and might not start dying en masse until decades after exposure.
In a 2013 study published online by the British Medical Journal, researchers tested 32,000 “anonymous appendix samples from people of all ages who had their appendix removed between 2000 and 2012.” Sixteen of the samples, which came from 41 hospitals across England, tested positive for the abnormal prion protein. This translates into one carrier for every 2,000 people in the United Kingdom, a scary number that gets even scarier if you project that out to 493 people per 1 million inhabitants. There are approximately 63.5 million people in the United Kingdom.
On a related but more upbeat note, scientists like Simon Mead and John Collinge, both of whom are experts in the field of kuru research, think there’s another reason why everyone exposed to prion-contaminated meat may not come down with a lethal neurodegenerative disease. As evidence they point to a common human gene (the prion protein gene, or PRNP) with a worldwide distribution. The researchers and their colleagues discovered a mutated form of this gene (i.e., a variant) in descendants of the Fore who survived the famous kuru outbreak. Initially, they hypothesized that this variant might have provided protection from kuru to the individuals who possessed it. These kuru-resistant survivors would have passed down their genes (and their resistance) to their descendants. In 2015, Collinge and his research team published a follow-up study in Nature in which they presented experimental evidence that when the genetic variant of PRNP was transferred to mice, it provided complete resistance to both kuru and classical CJD.
In a best-case scenario, thanks to what may have been their ancient ancestors’ brush with cannibalism (and kuru), at least some of the individuals consuming prion-contaminated meat in the 1980s were already resistant to the disease.52 If this is true, then the gloom-and-gloomers may be waiting for an epidemic that never arrives. From a therapeutic viewpoint, if these genetic variants can somehow be transmitted to humans, we may one day be able to confer resistance to the pathogens that cause spongiform encephalopathies—whether they turn out to be prions or viruses.