A Rochester, New York, resident might have caught one of the most frightening brain diseases around in one of the strangest ways possible—eating squirrel meat contaminated with zombie-like proteins.
The man’s bizarre story was included in a preliminary report released earlier this month at IDWeek, the annual conference of the Infectious Diseases Society of America. His case was one of several detailed by doctors from Rochester Regional Health, a major hospital network in the city.
According to the report, the 61-year-old man had been admitted to a hospital at Rochester Regional with cognitive impairment, schizophrenia, and psychosis in 2015; he was also unable to walk under his own power. But there was nothing to be done. Five months after his symptoms began, he died. Judging by his brain scans and other tests, the man had likely come down with variant Creutzfeldt-Jakob disease (vCJD), a form of the rare and universally fatal neurodegenerative ailment.
CJD is one of several diseases that are caused by a kind of protein known as a prion. Prions exist naturally in the brain and are seemingly harmless to us. But when these proteins start to fold in ways they shouldn’t, they force other nearby prions to misfold too, creating a growing army that, over years or even decades, effectively cannibalizes the brain.
Prion diseases can happen spontaneously or be passed down through families. But they can also be infectious, and some are even capable of spreading between different species of animals. These diseases are also called transmissible spongiform encephalopathies, a reference to the hollowed out, sponge-like appearance of the brain (at least when examined under a microscope) in someone who has died from it.
vCJD was first identified in 1996, when relatively young UK residents began dying unexpectedly from CJD. These victims had unfortunately eaten prion-infected beef from cows with their own form of prion disease, bovine spongiform encephalopathy (or what most people likely know as mad cow disease). And the cows had likely caught it from eating animal feed made with the infected brain matter of other cows as well as yet another animal vulnerable to prions, sheep.
There have only been around 200 documented cases of vCJD worldwide, with the majority occurring in the UK. Mad cow disease and its human variant never made huge inroads into the U.S., largely due to food safety practices that had barred farmers from feeding their cows food made from most other animals (the UK did the same in 1989, while also slaughtering hundreds of thousands of cows as a precautionary measure). Not everyone who eats infected meat seems to come down with vCJD either, likely meaning our genetics play a role there as well.
But as early as 1997, scientists in the U.S. have been worried about the possibility of regional delicacies such as squirrels and other hunted animals spreading prion disease. And in the man’s case, Live Science reported, the family told his doctors that he was an avid hunter and connoisseur of squirrel meat.
The authors of the report, led by medical resident Tara Chen, incidentally came across the case, not having treated the man himself. They began digging through hospital records after seeing four suspected cases of CJD crop up within the span of six months last winter—an unusually high number for a rare disease that affects about 350 people in the entire country annually. Of the five cases detailed in their report, however, two were eventually confirmed not to be CJD after all.
Though current tests can distinguish vCJD from the classical form of the disease, Chen told Live Science that it’s unknown whether the man was definitively diagnosed with CJD. With many fatal brain diseases, such as Alzheimer’s, doctors can only be sure of the diagnosis by examining the brain after death. If the man is confirmed to have had vCJD, he might very well be the only person ever known to have contracted it within the U.S. There have been four other officially recognized cases of vCJD in the U.S., and all are thought to have been exposed to it before they entered the country.
According to Live Science, Chen and her team are currently seeking permission to obtain the man’s medical records. to see if an autopsy diagnosis was made. By publishing their preliminary case report, they also hope to raise doctors’ awareness of CJD, noting that it took an average of two weeks to diagnose or rule out the disease in their cases. And that delay could raise the risk of cross-infection within hospitals, thanks to contaminated medical equipment that isn’t properly sterilized.
Adding to their zombie-like nature, prions can survive things that easily kill other pathogens, such as radiation and chemicals like formaldehyde.