Mosquitos carrying West Nile virus confirmed in Wisconsin after blood donor tests positive

The first report of West Nile virus activity has been confirmed in Wisconsin.

The Wisconsin Department of Health Services announced Monday that a healthy blood donor from Washington County had a blood screening that tested positive for the virus. Also, a dead bird in Chippewa County tested positive for the virus.

The DHS said the recent activity confirms there are mosquitoes carrying West Nile virus in Wisconsin. It’s not labeling the activity as a case.

“The positive blood donor is not considered a human case because they never developed any symptoms of West Nile Virus, which is required to be a probable or confirmed case,” the DHS said in a press release.

The Centers for Disease Control and Prevention says 80 percent of people infected with the virus don’t show symptoms.

Is more West Nile Virus activity expected in Wisconsin?

Elizabeth Goodsitt, DHS communications specialist, said West Nile virus is at its peak activity in Wisconsin, with August and September consistently having the highest reported activity.

“Most likely, we will see the first human West Nile virus disease case in the next few weeks and additional infections in animals or mosquitoes,” Goodsitt said in an email statement.

How severe is West Nile virus?

It’s rare in the United States for West Nile virus to become severe.

Only one in 150 reported cases have led to severe illness affecting the central nervous system, according to Goodsitt. Severe illness can lead to brain damage or even death.

Where in the United States has West Nile virus been confirmed?

The CDC states as of July 30, West Nile virus has been confirmed in 21 states, not including Wisconsin. Most of the states are in the South and Midwest. The map can be found on the CDC website.

What are the symptoms of West Nile virus?

Goodsitt said most people who test positive for the virus are asymptomatic.

One in five cases report having mild symptoms such as fever, rash, muscle aches, joint pain and nausea.

In very rare cases, severe illness can occur. Symptoms of severe illness include high fever, confusion and disorientation.

Goodsitt said people over age 60 are at greater risk for severe illness (2%) if they’re infected. People with other medical conditions such as cancer, diabetes, hypertension, kidney disease, and people who have received organ transplants are also at greater risk.

How does West Nile virus spread?

West Nile virus spreads through mosquito bites. The DHS urges Wisconsinites to be cautious of mosquitos. Goodsitt said mosquito bites can be prevented a number of ways:

• Avoid mosquito breeding sites. A map of the sites can be found on the DHS website.
• Apply an insect repellent containing DEET, picaridin, oil of lemon eucalyptus or IR3535 to exposed skin and clothing.
• Treat clothing with permethrin before heading outdoors but don’t apply permethrin directly to the skin.
• Wear long sleeves, long pants and long socks to prevent exposed skin.
• Consider rescheduling outdoor activities.