The New West: Prominent public health official shares frank thoughts about Chronic Wasting Disease

By Todd Wilkinson EBS ENVIRONMENTAL COLUMNIST

You may have seen Michael Osterholm’s name in a national newspaper because, as a global disease expert, he has investigated things like the deadly Ebola virus, and reporters have recently solicited his opinion about the rapidly-spreading coronavirus that started in China.

In 2019 I had a conversation with Osterholm, who is based at the University of Minnesota, about another zoonotic menace, one that is the deer-family equivalent of mad cow disease and is quickly exerting a presence in wildlife throughout the Northern Rockies: chronic wasting disease.

In February 2019 he offered this grave observation about mad cow to the Minnesota state legislature:

“It is my best professional judgment based on my public health experience and the risk of [mad cow disease] transmission to humans in the 1980s and 1990s and my extensive review and evaluation of laboratory research studies … that it is probable that human cases associated with the consumption of contaminated meat will be documented in the years ahead. It is possible that the number of human cases will be substantial and will not be isolated events.”

Here are some excerpts from our conversation:

Todd Wilkinson: What caused you to deliver such a forceful warning before the Minnesota legislature?

Michael Osterholm: Several things. First of all, it’s one of those things, like so many issues, that I could work 28-hours-a-day on. I’ve been very involved with influenza outbreaks and other diseases, like Ebola, and traveling 200,000-miles-a-year for work. CWD should be regarded on the same scale of other diseases we are worried about.

I just became more and more unsettled about this issue. I had been involved with providing professional input in the 1980s on BSE [bovine spongiform encephalopathy, or mad cow disease]. And at that time had expressed my severe concern about this idea that there was this magical disease barrier existing between species that would keep everything from coming to humans. It was something I thought was naïve and my suspicions were validated.

At the time, some said you were just a scare monger, that kind of person who just needlessly upsets people. And, of course, the story’s been told since that time. I wasn’t alone and our worries were indeed justified.

TW: What’s needed?

MO: We ought to aggressively be developing testing methods that can be done on site, [and are] reliable, cheap and effective.

The last thing we want to have happen is for hunting as a tradition and a management tool to be reduced. Right now there are 200,000 white-tailed-deer-a-year that are harvested in Minnesota and if we suddenly saw the white-tailed deer hunting experience change, that’s only going to increase the problem on the wildlife side because of the animal population density [and having higher concentrations of animals with CWD coming in closer contact with uninfected animals]. However, we need to face the facts and make sure people are protected by providing the best available knowledge.

TW: You have called attention to the risk of CWD animals passing through meat processing facilities.

MO: Yes, the second thing I’m very concerned about, and it comes from some of my foodborne disease work … is what the hell happens when you introduce CWD into meat processing environments? If somebody’s deer or elk comes through and it’s contaminated, what does that mean for everything else behind it? I’ll tell you: it’s not good because it’s not easy to sterilize and decontaminate places and surfaces that become tainted with prions.

TW: You’ve taken your concern a step further, emphasizing your fear that with potential prion mutation, CWD could cross a species barrier from cervids to domestic livestock and then reach people.

MO: Something that’s been very concerning is the lack of national leadership, whether it be on the wildlife side or on the agricultural side. Clearly, I think we have some serious challenges here with what it means to the bovine world.

Is there going to be potential cross exposure [to cattle] and would that happen? The ag people can’t just back out of the conversation about it potentially reaching livestock and, of course, public health officials need to be paying attention to the human side. The World Health Organization and CDC advisement to not eat suspected meat is limp compared to what we need. A lot of CWD-infected deer and elk may not look sick.

I’m not telling anybody this [CWD] is going to be a BSE crisis but I am suggesting that it could be. Why do we want to experiment with ourselves to find out?

TW: As CWD continues to spread, what are your priorities?

MO: I absolutely have no doubt that animal-to-animal transmission is really important. How much of that is from direct saliva contact is really unclear. I think the human exposure question involves really, for me, the venison and game meat consumption issue. The extent of using your own utensils and knives in butchering deer or elk and bringing it back to the kitchen raises serious questions about contamination. And, in terms of people coming in contact with lymph nodes and other tissue of infected animals, we just don’t know the degree of risk but that doesn’t mean risk doesn’t exist.

TW: We know that there are different prion strains and mutations that can occur. Is your concern that it’s only a matter of time?

MO: That’s part of it; actually, it’s all of it. Look at the accelerating number of cases. This is out of control in the wildlife populations.

Todd Wilkinson is the founder of Bozeman-based “Mountain Journal”  and is a correspondent for “National Geographic.” He’s also the author of “Grizzlies of Pilgrim Creek” about famous Jackson Hole grizzly bear 399.