(Journal stock photo)

MARQUETTE — The Marquette County Health Department said last week that West Nile virus has returned to the region after laboratory testing revealed its presence in a crow earlier this month.

West Nile virus has been reported in mosquito populations around Michigan and the Upper Peninsula since 2001, and the rest of the continental United States since 1999, according to CDC statistics. Cases of West Nile virus occur during mosquito season, which starts in the summer and continues through fall. The virus is most commonly spread to people by mosquito bites. Mosquitoes become infected by biting infected birds. Some predatory birds become infected after eating sick or dead birds that were already infected with the virus.

“This is not new,” said Marquette County Health Director Terry Frankovich. “The virus arrives in the U.P. annually.”

Frankovich said every year surveillance testing is done on birds to identify when the virus arrives to the region.

Since its discovery in 1999, the virus has been found in over 300 species of birds around the U.S., according to the CDC.

Symptoms of the West Nile virus occur three to 15 days after infection from a mosquito bite and some people may not have any symptoms at all, Frankovich said.

“Most people who become infected don’t have any symptoms. So it could certainly be in a community without you being aware, and birds are an excellent way to test to know,” she added.

About 20 percent of people who become infected with West Nile will develop mild symptoms and about 1 in 150 people will develop serious symptoms, which may include fever, headache, body aches, swollen glands and skin rash, Frankovich said. In very rare cases, the virus can lead to neuroinvasive diseases like encephalitis or meningitis.

“One-in-10 out of that 1-in-150 could become fatally ill,” she stated.

People who are experiencing symptoms of West Nile virus are encouraged to contact their local health care provider. The risk of contracting the virus can be lowered through basic mosquito prevention measures, such as wearing long-sleeve shirts and pants when outside, using DEET-based bug sprays, effective screening of windows in homes, avoiding mosquito breeding habitats and using mosquito netting over strollers when outside.

“No vaccine or specific antiviral treatments for West Nile virus infection are available,” the CDC website states. For more information on West Nile virus, individuals can visit the CDC’s website at www.cdc.gov/westnile/.

Von Lanier can be contacted at 906-228-2500, ext. 254.