Deer in Iowa have been infected with COVID-19, according to a recent study conducted by university researchers, including those from Penn State and Iowa State, as well as Iowa wildlife officials. This study has not been peer-reviewed yet, but the researchers “found the results so disturbing that they are alerting deer hunters and others who handle deer to take precautions to avoid transmission,” according to The New York Times.
A survey done from January 2020 to March 2021 by the United States Department of Agriculture’s Animal and Plant Health Inspection Service found COVID antibodies in white-tail deer in Illinois, Michigan, New York, and Pennsylvania. The more recent study found active COVID infections among Iowa’s white-tail deer populations.
According to the study, the researchers tested retropharyngeal lymph nodes of 151 free-living and 132 captive deer in Iowa from April 2020 to January 2021. Of all of the deer tested, around 33% tested positive for COVID. However, a little over 80% of another group of deer tested between November 2020 and January 2021 were infected with COVID.
With what is known about white-tail deer and COVID so far, to what extent is the Island at risk?
“It’s certainly being discussed among various people [on the Island],” Richard Johnson from the Martha’s Vineyard Tick Program told The Times. He also said there are an estimated 40 deer per square mile on the Island. “It’s probably a good idea to take precautions just in case it’s here. We don’t know if it is, but we don’t know if it isn’t either.”
These concerns especially affect the Island’s Deer Management Program, a collaborative effort among the Island Grown Initiative, the Martha’s Vineyard Agricultural Society, and the Martha’s Vineyard Tick Program. One part of the Deer Management Program that is taking precautions is the venison donation program, which accepts extra meat from hunters and distributes cooked venison meals to Islanders in need.
Rebecca Haag, executive director of Island Grown Initiative, said they are following safety protocols when handling the deer meat, such as wearing masks and gloves and cooking at 165 degrees Fahrenheit, which is the Massachusetts Department of Fisheries and Wildlife’s (DFW) recommended temperature to cook game meat at to kill pathogens. Haag said most hunters on the Island fortunately already practice hunting safety measures. The Iowa cases have been shared with the Island’s health agents and those working in the venison donation program will continue to keep in place safety measures and warn people to stay vigilant about the deer-COVID news developments, Haag said.
DFW has already been and continues to monitor the situation of deer and COVID, according to Martin Feehan, the deer and moose project leader at DFW’s Westborough Field Headquarters.
“Although there is no direct evidence of COVID-19 in deer in Massachusetts, published studies and unpublished surveillance throughout North America have found the presence of COVID-19 in white-tailed deer. The prevalence rates have varied regionally, but there haven’t been cases of populations appearing entirely negative [in cases] in 2020 and 2021,” Feehan wrote in an email. “This would suggest that COVID-19 is already present in deer populations in Massachusetts. There is no evidence currently that COVID-19 adversely impacts white-tailed deer and no mortalities have been reported.”
According to the DFW website, a study done by Ohio State University using polymerase chain reaction testing on its deer found that while COVID can spread among the animals’ populations, they are contagious for only about seven days. Additionally, Feehan said there is currently “no direct evidence humans can contract COVID-19 from white-tailed deer.” However, to mitigate risks hunters and others should follow best practices of handling wild game meat since it is still uncertain.
Other New England states, such as Maine and Vermont, are also monitoring the situation of deer and COVID, according to Bangor Daily News and Burlington Free Press respectively.
Sam Telford, an epidemiologist and a professor of infectious diseases at Tufts University, said COVID is a respiratory disease, so it is unlikely people can contract the virus from deer meat or blood. Telford said exposure to respiratory secretions or lung tissue is the more likely path to COVID infection if the deer can spread the virus to humans. Johnson said many deer hunters who use bows and arrows target the lungs for a swift kill.
“As an epidemiologist, I tend to look at empirical evidence. Archery season has been ongoing for almost two months in other states, such as Ohio and Pennsylvania, where SARS-CoV-2 has been detected in deer. We have not heard of hunters mysteriously getting COVID, or at least not at a rate any different than the general public,” Telford wrote an email. “That tells me that the probability is pretty small that a hunter is at risk. Very much like tick-borne infections, hunters do not appear to get infected at a rate any greater than the general public despite their exposure to tick-infested deer or to blood and tissues of deer that have had many many ticks on them.”
Telford said most preparation of freshly-killed deer is done outdoors, so environmental elements like sunlight and wind reduce the risk of infections.
“Once the deer has been dead a while, maybe a day or more, then even if it had a lot of virus in its secretions it would be much less infectious,” Telford said. “There is a significant decline in virus viability in carcasses over time. So, by the time hunters or processors cut the meat up, there may be very little infectious virus even if it was present in blood or muscle.”
Johnson said another concern people have voiced is whether the deer populations could act as a reservoir for COVID to mutate into a variant that can be spread back to humans.
“The more places, the more animals and humans this virus is living in and moving around, the more likely it is to mutate into something a much more dangerous form,” Johnson said. “That’s the real worry in my mind, and I think public health people will agree. ”
Telford said there are many COVID variants, but only a handful are of “public health significance.” He said the ramifications of the COVID virus circulating in deer populations remain to be seen. At this time, it is still unknown how deer contracted COVID, although Telford said there is a yet-to-be-peer-reviewed study that detected rare COVID genotypes in deer. He said this suggests a possibility COVID is generated within the deer. Telford believes a better idea of the severity of the situation will be known by the first of 2022 when hunting seasons in the eastern regions of the United States are largely over.
“Viruses circulating in different kinds of animals could undergo small mutations that could better adapt them to those animals. Whether those changes imply anything to humans is not clear,” Telford said. “I still think that the virus is doing pretty well in humans and that the emergence of new variants from animals is probably less likely than variants emerging from the huge number of people out there.”