Five Michigan DNR workers contracted tuberculosis, likely from testing deer

Deer heads are prepared for testing at the Michigan Wildlife Disease Laboratory in East Lansing, in this 2017 photo. (Courtesy photo by Anna Mitterling)

Five workers at Michigan’s Wildlife Disease Laboratory have been diagnosed with tuberculosis, possibly linked to “human error” as the lab struggled to test thousands of deer for chronic wasting disease, a Bridge Magazine investigation found. 

The Department of Natural Resources — which has made no public announcement — confirmed the TB cases in response to inquiries from Bridge Magazine this week. The infected workers have undergone several months of antibiotic treatment, and hundreds of other DNR employees were offered testing. 

The outbreak, the first of its kind at the 10-person lab, was diagnosed last summer. Workers at the lab were conducting tests on thousands of deer in search of two challenging diseases: chronic wasting disease and bovine tuberculosis, which is commonly found in cattle but also in deer and other animals. 

The state theorizes the workers likely contracted the disease from white-tailed deer with bovine TB, according to state records Bridge received through a public records request. Almost 36,000 deer were tested for the disease in 2018, about 12,500 more than the year before.

State lab workers have raced to test deer as part of an effort to contain chronic wasting disease (CWD) after a so-called zombie deer was identified near Lansing in 2015.

“In 2019 – after we became aware of the [TB] infections – we scaled back the number of deer tested, in addition to reducing the hours employees were working during any given day at the lab,” DNR spokesman Ed Golder told Bridge in an email Wednesday.

“It’s conceivable the increased volume in 2018 led to human error or some other problem [that led to human infections]. We’re not certain,” Golder wrote. “Reviews by external agencies … weren’t able to draw any definitive conclusions about the cause of the infections.”

The disease lab is housed at the Michigan State University Veterinary Diagnostic Laboratory in East Lansing. Officials said worker exposures to tuberculosis were the first in 25 years of state testing for bovine TB in deer.

A DNR lab supervisor said it remains unclear what if anything the workers did, or did not do, that left them vulnerable to infection. 

“There was no documented incident. There wasn’t anything we could pinpoint. There wasn’t anyone who did anything wrong,” lab supervisor Kelly Straka told Bridge. “I can tell you that it has never happened before” in her career. “As someone who cares about their staff, it is upsetting.”

Bovine TB is a bacterial disease that primarily affects cattle, but deer in a northeast area of the Lower Peninsula have also contracted it. The disease, similar to human TB but more infectious, commonly involves the lungs and can lead to death. Bovine TB is also known to infect people, but deer-to-human transmission is extremely rare.

The five lab workers were diagnosed with a “latent” form of TB which can lie dormant for years and is not infectious to others unless it becomes active, which may never happen, DNR officials said.

The state never announced the cases publicly. In fact, DNR records obtained by Bridge suggest the department was keen on keeping the outbreak quiet. One DNR supervisor was threatened with punishment after he told a hunting group about the cases, according to personnel records obtained under the state Freedom of Information Act.

DNR supervisors issued a “notice of formal counseling” to Upper Peninsula wildlife supervisor Terry Minzey after he told a hunting group of the TB cases last summer. 

Minzey was accused of “sharing both inaccurate information and information without authorization” at an Aug. 10 meeting of the Upper Peninsula Sportsmen’s Alliance in Skandia, near Marquette.

“It is expected that at Division and Public meetings you share only accurate and authorized information,” deputy DNR chief Shannon Hanna wrote Minzey in the document, dated Oct. 16. “Failure to comply with this direct order may result in disciplinary action.”

Minzey objected to the findings. In his response, he said most of the information he provided to the hunters came from a widely distributed email to supervisors sent on July 9 to Wildlife Division staff.

“This was distributed to more than 200 employees and not marked confidential,” Minzey wrote. “There was no investigation conducted. I was never presented with the charges nor given an opportunity to respond to these charges.”

Two previous job evaluations obtained by Bridge rated Minzey as “high performing,” and praised him for being attuned to the political dimensions of DNR’s work.  

“He always keeps the Chief and I informed of what is going on in the U.P. that may or may not end up causing problems in Lansing,” then-deputy chief Steven Chadwick wrote in 2017.  

Golder, the DNR spokesman, would not comment on the action taken against Minzey, except to say, “We don’t discuss personnel actions, but I believe you have Terry’s records.”

Golder also said it was not necessary for DNR to publicly announce its lab workers had contracted tuberculosis because there was no infection threat to others and DNR wished to protect employees’ private health information.

“This is a small work group,” Golder said. “Revealing that there is an infection for any individual in that group will lead to questions for everyone in that small group.”

Transparency, or the lack of it, has been a problem for the DNR recently.

A Bridge investigation published in November showed that DNR leaders blocked the release of documents for years that contradicted the department’s rationale for killing federally protected gray wolves. 

State workers offered TB testing 

Records show DNR sent an email to volunteers last summer offering them the same TB skin checks given to Wildlife Division staffers. Golder said he did not know how many responded and sought testing.

Lab staff are routinely given a baseline TB skin test, then retested about six months after each deer season. Three staffers were identified as contracting TB last June and two more later in the summer.

All had negative follow-up chest X-rays and no symptoms, Golder said, indicating that their TB was inactive. DNR cautioned that it’s not known to a certainty the workers’ tuberculosis was actually contracted from the deer, given its dormancy. 

“There are no cultures to test,” said Straka, the lab supervisor. 

But the lab’s heavy workload in trying to identify and contain chronic wasting disease in Michigan deer is suspected as having played a role, according to the email to volunteers sent by a lab scientist, Melinda Cosgrove.

There is no way to pinpoint exactly when or how the exposure happened,” Cosgrove wrote. “However with the increased testing demands and extended staff hours, it is possible that the exposures are a result of exceeding the capacity of our laboratory infrastructure.”

The wildlife lab tests for a range of animal diseases. Hunters submit the heads of deer they have killed to be tested for bovine TB and CWD. Lab workers typically wear protective clothing, including masks, goggles and respirators in some situations.

“We have added additional precautions that go above the typical protocols at this level of work, such as wearing respirators for all necropsies,” Golder said in an email. 

The DNR has also reduced the “volume of deer moving through the lab,” he added. Deer testing was cut by more than 10,000 animals last year, to about 25,000, because of the positive TB tests, Golder said.

The governor’s budget for next year seeks $300,000 to cover increased lab costs and $2 million in one-time funding for CWD research. 

Michigan is the only state where bovine TB is endemic, meaning it can survive indefinitely at low levels in a species. Almost all infected deer have come from 570 square miles in the northeast Lower Peninsula dubbedClub Country” for the large number of private hunting ranches.

The deer management unit encompasses the four corners where Montmorency, Oscoda, Alpena and Alcona counties meet. Nearly 80 percent of TB-infected deer are from there, the DNR says.

Last year, more than 3,000 deer were tested from the four counties; 29 cases were found, about the same as the year before. No incidences of bovine TB in deer were detected in Michigan’s other 79 counties.

There have been 77 cattle herds found contaminated since the first herd was identified in 1998. The most recent was in January in Alcona County.

Underscoring the rarity and seriousness of deer-to-human transmission, the U.S. Centers for Disease Control and Prevention identified just three known cases in a study it published last fall. All involved hunters in Michigan since 2002, confirmed by genetic testing of some 900 deer samples collected by the state beginning in 1995.

One was a 77-year-old hunter in northeast Michigan whose active TB in 2017 was linked to a strain circulating in deer where he lived a decade earlier. 

Two previously known cases — in 2002 and 2004 — were more solidly confirmed in the same genetic study. One hunter had a cut finger while cleaning the deer; another is believed to have inhaled microscopic particles from an infected deer while field dressing the animal.

Dr. Laura E. Power, an epidemiologist in the School of Public Health at the University of Michigan and co-author of the study, told Bridge these earlier cases highlight clear genetic proof of deer-to-hunter transmission.

Power said DNR lab workers are at much higher risk than hunters.

“They are around zoonotic threats all day long,” Power said. “You don’t want panic. This is still very uncommon.”

About the author

John Barnes worked at The Grand Rapids Press and for 33 years. He specialized in investigative journalism and most recently oversaw journalism projects for’s eight newspapers statewide. Barnes has reported extensively on gun rights, criminal justice, traffic safety, the outdoors and medical issues.

Facts matter. Trust matters. Journalism matters.

If you learned something from the story you're reading please consider supporting our work. Your donation allows us to keep our Michigan-focused reporting and analysis free and accessible to all. All donations are voluntary, but for as little as $1 you can become a member of Bridge Club and support freedom of the press in Michigan during a crucial election year.

Pay with VISA Pay with MasterCard Pay with American Express Donate now

Comment Form

Add new comment

Dear Reader: We value your thoughts and criticism on the articles, but insist on civility. Criticizing comments or ideas is welcome, but Bridge won’t tolerate comments that are false or defamatory or that demean, personally attack, spread hate or harmful stereotypes. Violating these standards could result in a ban.

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.


B McCready
Fri, 03/06/2020 - 8:46am

Did I read this right? 29 positive tests in the deer and 5 workers out of 10 infected? That sounds like pretty significant deer to human transmission to me.

Fri, 03/06/2020 - 10:12am

Incredibly sloppy lab work (just look at what the worker pictured is wearing). Scary.
This needs to be thoroughly investigated by independent sources.

Fri, 03/06/2020 - 1:05pm

Do tell, Rick. You're a wildlife biologist? Lab technician? Some guy who saw something like it on TV? The article indicated they've been doing this for something like 40 years with zero problems, and that they follow all the guidelines. But you know better, right?

Alex Sagady
Wed, 03/11/2020 - 11:24pm

>>>>>>he article indicated they've been doing this for something like 40 years with zero problems, and that they follow all the guidelines.

Your comment does not change the fact that the Michigan Department of Natural Resources
committed a violation of Michigan occupational health protection laws by allowing their
lab workers to become infected with TB. It is the responsibility of employers, including
government, to provide a workplace that is free of occupational health hazards, including
TB infection from animal specimens in a government laboratory.

The article does not identify the "guidelines" allegedly used by MDNR and whether
they conformed to Michigan State Univesity lab biosafety protocols:

Fri, 03/06/2020 - 1:04pm

Why are "human error" and "latent" in quotes? Are you trying to cast aspersions on the veracity of the claims?

John Barnes
Fri, 03/06/2020 - 1:42pm

Hi Matt, The quote marks signify that "human error" is from a direct quote, which is a few paragraphs lower. "Latent" TB is the same; meant to show that is the exact word the CDC and medical experts use. Thanks for reading.

Alex Sagady
Fri, 03/06/2020 - 3:56pm

This article does not say whether or not this failure of occupational health
protection for MDNR public employees came to the attention of
occupational health regulators in Michigan, or whether MDNR or MSU was
cited for lapses in occupational disease protection requirements for lab workers.

S Baker
Fri, 03/06/2020 - 3:59pm

Why the secrecy from DNR? Hiding public health information is never a good plan, and smart hunters understand the nuances.
If Latent TB infections (LTBI) are not treated, 5-10% develop TB at some point, which is also good information. DNR is funded by recreation fees (vehicle license renewals), boat registrations, hunting & gun sales (federal), etc., thus DNR's actions impact many.

Sat, 03/07/2020 - 5:57am

His only credentials needs to be a US citizen to be rightfully concerned about this serious health risk that is not being taken seriously enough at the levels that it should be. Demeaning and bullying those that are giving this issue the important attention that it deserves is an un-American response to revealing facts that can lead to the right solutions to prevent harsh or widespread illness. Our taxes have been paid for the public, and especially the workers, to be informed of health hazards. Hindering that information promotes the threat to all.

Justa Michigan ...
Sat, 03/07/2020 - 7:06pm

I heard about Michigan deer having tuberculosis well over a decade ago. Why is it that the DNR claims that they are just finding out? I'm not buying it.

Graham Hickling
Thu, 04/16/2020 - 3:35pm

You would have heard about TB in Michigan deer “more than a decade ago” from reports by the MDNR Wildlife vets, who have been working on this problem since the mid-90s.

Grossed Out
Tue, 06/02/2020 - 1:41pm

This is all nasty. People are killing deer, gutting them, eating them. I want to vomit. Imagine how many hunters and their families must be infected. They don't wear anything at all near that protective lab gear when "dressing"/preparing/eating that flesh. People go vegan! God is talking to us, but few are listening.