RIVER FALLS, Wis. — A dead crow found in the River Falls area has tested positive for the West Nile virus, and officials are alerting residents to the possible danger.

“It’s in our county, in our area, so the big message is people should take precautions to avoid mosquito bites and do away with places of standing water where mosquitoes breed,” said Sue Galoff, Pierce County Public Health director.

West Nile virus is spread to humans through the bite of an infected mosquito. Mosquitoes get the virus by feeding on infected birds — usually crows, but also ravens and blue jays.

Galoff wouldn’t say where in River Falls the infected crow was found.

“There’s no need to pinpoint it,” she said. “That would only give some people a false sense of security that the virus isn’t near them. Birds fly, so the virus has arrived here.”

The Pierce County Health Department’s information on West Nile says that most people infected with the virus don’t get sick. Those that do usually have mild symptoms — fever, headache, muscle ache, rash and fatigue.

Less than 1 percent with the virus get seriously ill with a high fever, muscle weakness, stiff neck, disorientation, mental confusion, tremors, confusion, paralysis and coma. Older adults are more susceptible.

Galoff said this is the time of year for West Nile to emerge.

“We rely on people to bring in dead birds for testing that are found in their yards and pastures,” she said.

Those birds are packaged and sent to the Wisconsin Department of Health Services in Madison.

Galoff said last year there were no human West Nile cases in Pierce County and anywhere nearby, but there were six cases in Wisconsin. One person died.

Suggestions to minimize the threat of West Nile:

— Limit time spent outside at dawn and dusk when mosquitoes are most active

— Apply insect repellent to clothing and exposed skin

— Make sure window and door screens are in good repair

— Clean roof gutters and downspouts for proper drainage

— Properly dispose of items outside that hold water, including old tires

— Clean and chlorinate swimming pools, outdoor saunas and hot tubs

— Turn over wheelbarrows, wading pools, boats and canoes not in use

— Trim tall grass, weeds and vines since mosquitoes rest there during hot daylight hours

— Landscape to prevent water from pooling in low-lying areas

Wisconsin documented its first human West Nile virus infection in 2002. Human infections typically occur in August and September but as early as June.