Wild deer have coronavirus? Iowa study says yes -- perhaps 80%.

Nov. 6—A study of wild deer in Iowa has found that coronavirus infections blossomed — perhaps to around 80 percent — last year as the outbreak was surging among humans during the fall hunting season.

This week's announcement of the findings come as hundreds of thousands of deer hunters in Minnesota prepare to take to the fields, forests and farms Saturday for the state's regular firearms hunting opener.

The risk to hunters is likely small, health officials and researchers said, especially compared to risks associated with everyday interactions with people, as well as at "deer camp," where generations of families often spend time together inside cabins. There's no evidence you can get COVID by preparing or eating food, so the venison is safe.

The risk to deer is unclear; researchers tested deer that were killed by hunters or vehicles, so it's unclear if they were sickened by the virus.

Beyond immediate health risks to deer or people, the news carries potential ramifications for the coronavirus, which could find a "reservoir" in wild deer that could potentially lead to mutations that could potentially jump back to infect humans.

The findings of researchers at the Iowa Department of Natural Resources and Penn State University have not been peer-reviewed but were verified by federal scientists at the National Veterinary Services Laboratories, the New York Times reported.

Unlike previous studies of wild deer, which only confirmed exposure to SARS-CoV-2, the virus, the PCR testing of glands done on the Iowa deer confirmed active infection of COVID-19.

"This is the first direct evidence of SARS-CoV-2 virus in any free-living species, and our findings have important implications for the ecology and long-term persistence of the virus," Suresh Kuchipudi, clinical professor of veterinary and biomedical sciences and associate director of the Animal Diagnostic Laboratory at Penn State, said in a statement accompanying the announcement of the findings. "These include spillover to other free-living or captive animals and potential spillback to human hosts. Of course, this highlights that many urgent steps are needed to monitor the spread of the virus in deer and prevent spillback to humans."

80 PERCENT POSITIVITY

What was most striking about the findings was how widespread the infections were, researchers said. At one point from December 2020 to January 2021, more than 80 percent of whitetail deer sampled from different parts of the state tested positive. That was the same time that the coronavirus was surging in Iowa — but some 50 times more prevalent among the deer. That's especially remarkable because as a general rule deer travel far less distance than people and don't congregate in huge indoor groups like we do.

Scientists suspect that deer became infected by people, although it's not clear how that might have occurred.

There are two bits of evidence supporting that notion.

First, genetic sequencing of the deer samples revealed that deer were catching the same variants of the coronavirus that were circulating among Iowans at different times of the year. Furthermore, multiple "geographically confined herds" experienced outbreaks, said Vivek Kapur, a professor of microbiology and infectious diseases at Penn State. That, he said, suggested "multiple independent spillover events from humans to deer, followed by local deer-to-deer transmission."

Second, the prevalence of COVID among wild deer increased as the hunting season progressed from archery into firearms seasons, when an increasing number of hunters take to the wild.

But how humans are transmitting the virus to deer, or how much of the spread might be from, say, a pugnacious and amorous buck roaming the countryside, clashing antlers with other males and mounting females, remains unclear.

The Minnesota Department of Natural Resources has no immediate plans to begin testing wild deer for COVID, said Barb Keller, the DNR's big game program leader.

However, she said, researchers from the University of Minnesota are planning to test at least some deer samples that the DNR will make available to them from the DNR's collection sites to monitor the spread of chronic wasting disease, an always-fatal-to-deer disease that is slowly spreading.

"My takeaway from this research is there are still a lot of unknowns right now," Keller said. "I did think it was surprising how widespread the infections were, but we don't really know if the deer were sickened."

ADVICE TO HUNTERS

Keller said she'd "fall back" to basic recommendations for successful hunters who typically gut a deer in the field soon after killing it: "Take precautions when handling the animal. ... If a deer looks sick, don't consume it, and always make sure the meat is appropriately cooked to the right temperature."

Hunters who are especially concerned about contracting the coronavirus from a deer should consider wearing a mask while gutting the animal, which usually involves cutting it open and reaching elbow-deep into its chest cavity to cut or tear out its lungs and windpipe.

Doug Schultz, spokesman for the Minnesota Department of Health, offered this:

"While the risk of acquiring COVID from wild deer is low, we would advise deer hunters to take precautions when dealing with white-tailed deer: wear rubber gloves and perhaps a mask when field dressing and processing; sanitize hands and instruments after dressing; and bag carcass remains before disposing in trash. Eating cooked venison carries little risk as long as it reaches an internal temperature of 165°F. The safety measures for hunters outlined on the CDC website are good general practices to protect hunters from a myriad of diseases."