New evidence about chronic wasting disease leads health officials to reconsider their advice

Canada’s leading pathologist on mad cow disease shook up the deer hunting world this year when she delivered to an international gathering of prion disease experts an alarming study with implications for human exposure to chronic wasting disease (CWD).

By feeding moderate amounts of diseased venison to macaques monkeys over a period of years, Dr. Stefanie Czub found what no one wanted her to find: CWD can be transmitted to non-human primates who are genetically close to humans.

In an interview with the Star Tribune last week, Czub (pronounced Shoob) said she quietly revealed her study findings to the U.S. Centers for Disease Control and Prevention (CDC) before announcing the preliminary results in May at the Prion 2017 conference in Edinburgh, Scotland.

In turn, just before this year’s deer and elk hunting seasons, America’s top public health agency “strongly’’ recommended that hunters who harvest deer and elk in CWD-infected zones have the animals tested before eating the meat.

Czub takes it a step further. Her advice to North American whitetail hunters, including the 500,000 people who will hunt deer this year in Minnesota, is to test your kill regardless of where you harvest it.

“This is a disease with a long, extended incubation period,’’ said Czub, a professor, veterinarian and researcher at the University of Calgary who also works closely with the Canadian Food Inspection Agency. “It’s not your average food poisoning.’’

To Minnesota State Public Health veterinarian Joni Scheftel, the most compelling aspect of Czub’s research is that two test monkeys became infected with CWD prions after eating muscle meat from infected whitetails that appeared healthy at the time of their death. Prions are abnormal proteins that cause fatal nervous system disease.

“It certainly got all of our attention in public health,’’ Scheftel said of Czub’s research project, now in its ninth year.