Cause of wonky brain proteins remain mystery after 30 years

Jay Ingram threw a mousetrap into a nest of other mousetraps set to spring. The resulting chain reaction, with traps snapping and leaping off the table, was a quick and noisy way to illustrate his point about prions.

Ingram, a former radio and television host and author, threw his mousetraps during the Prion Diaries, a speaking tour to Alberta’s four agricultural colleges during the week of Nov. 12.

“That’s what happens in the brain,” he told a Lethbridge College crowd.

“You introduce prion proteins that are misfolded into the brain and somehow … there’s some kind of contact, nobody really knows how.… you get this contact and it spreads and it causes diseases and in every single case, it’s invariably fatal.”

BSE is the best known disease attributed to prions, which are misfolded proteins.

Ingram gave a history of BSE’s discovery and handling in Europe, dating back to the mid-1980s, and its appearance in Canada in 2003.

However, he also apprised his audience of similar brain diseases that he said are cause for concern.

Among them are chronic wasting disease, a brain disease primarily found in deer that also has potential to infect elk, moose and caribou.

CWD was first found in captive Colorado deer in 1967 and has spread to at least 18 U.S. states and Saskatchewan and southeastern Alberta.

“It’s the biggest biomass of prions in the world right now, chronic wasting disease,” said Ingram. “(There are) more chronic wasting disease prions in both captive and wild animals than any other prion disease.”

Although CWD has been known for 40 years, it remains uncontained and can be spread by wild animals through saliva, urine, feces and placenta, Ingram said.

“I’ve heard people say they think that ultimately vast numbers of deer, elk, caribou and moose might be susceptible.”

Dr. Stephanie Czub, research manager for the Canadian Food Inspection Agency in Lethbridge, said CWD is uncontrollable because of wild animal movement, migration and methods of spread.

She said management is the remaining option, which includes restrictions on farmed elk and deer, double fencing and limited contact between captive and wild ungulates.

“And this is barely managing it. It’s not controlling it,” said Czub.

Kevin Keough, executive director of the Alberta Prion Research Institute, said he isn’t ready to agree that the CWD situation is uncontrollable.

“There may be some possibility to control CWD with a very effective vaccine,” he said. “We and others are investing money in looking at the potential for vaccines. Administering effective vaccines in the wild, though, is an extremely difficult thing to do and usually when you’re doing it, you’re doing it against an agent that doesn’t hang around for 40 years (as prions do).”

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