Ruffed grouse in northern Minnesota test positive for eastern equine encephalitis virus

Ruffed grouse in northern Minnesota test positive for eastern equine encephalitis virus Photo: KSTP

Updated: November 18, 2019 01:20 PM

Three ruffed grouse in Itasca County have tested positive for a mosquito-borne virus called eastern equine encephalitis (EEE), marking the first time the virus has been confirmed to cause illness in a Minnesota wild animal.

The Minnesota Department of Natural Resources said EEE is a rare illness in humans, and people bitten by infected mosquitoes seldom develop any symptoms, but it can be serious if they do.


The hunters who harvested the grouse brought them to DNR staff late last month after noticing abnormal behavior in the birds and reduced muscle mass. The DNR said samples from the birds were submitted to the University of Minnesota's Veterinary Diagnostic Laboratory (VDL), and tests concluded two and possibly the third were infected with EEE.
The EEE virus typically is found in the eastern United States and along the Gulf Coast.  It has also been found in other states, including Michigan and Wisconsin, according to the DNR.

"Now that we've found the EEE virus in Minnesota grouse, we will continue to monitor grouse populations for signs of the disease," Michelle Carstensen, wildlife health program leader for the DNR, said in a statement. "It's too soon to say how widespread the EEE virus might be in grouse populations because we only have one year of grouse sampling results from 2018."

"It is rare for us to find EEE in Minnesota, but this year we've diagnosed the virus in these grouse and a horse," said the VDL's Dr. Arno Wuenschmann. "I initially suspected that West Nile virus caused the encephalitis, but molecular tests conducted on the grouse in collaboration with the Animal Health Diagnostic Center at Cornell University proved EEE virus was to blame."

Before this discovery, the DNR said wolves and moose in northeastern Minnesota had been exposed to the virus, but animals of either species were never found to be sick with the disease.

In 2018, the DNR began asking hunters to submit grouse samples for West Nile virus testing. Samples collected the first year showed 12 percent of the birds had been exposed to the West Nile virus, but none had been exposed to EEE.

As with any wild game, the DNR urged care when processing animals to avoid cuts that could cause potential infection. Any game that appears abnormal – either in the field or after dressing shouldn't be consumed. Hunters with questions about what they harvest can contact a nearby DNR area wildlife office.

Connect with KSTP

Join the conversation on our social media platforms. Share your comments on our Facebook, Instagram, and Twitter pages.



Copyright 2019 - KSTP-TV, LLC A Hubbard Broadcasting Company


Police investigating after 3 found shot to death in Apple Valley home

On night of Nevada caucuses, Klobuchar returns to Minneapolis for fundraiser

UPDATE: 1 dead in Hennepin County small plane crash

More pleasant weather to come on Sunday

KSTP Sports Girls' State Hockey Central

Officials: Fire at Becker recycling facility extinguished