West Nile kills crow in county

JEFFERSON — Jefferson County has recorded a confirmed case of the West Nile virus killing a crow.

This marks the first bird that has tested positive for West Nile in Jefferson County since surveillance for the mosquito-transmitted virus began May 1.

“The positive bird means that residents of Jefferson County need to be more vigilant in their personal protective measures to prevent mosquito bites,” Jefferson County Health Department director Gail Scott said.

Since a dead bird has been found, no additional testing will be conducted by the state within Jefferson County, as there likely are many more birds that have West Nile within the county, she said.

Originally from Africa, the virus first appeared in the United States in 1999 in the New York City area. The first human cases were identified in Wisconsin in 2002.

West Nile virus is carried by mosquitoes and transmitted through a bite by an infected insect. Mosquitoes become infected with the disease by feeding on infected birds and their bite can infect humans.

Scott reported that, typically, infected birds precede any human cases in an area, but it is not inevitable that human infections will follow.

“Jefferson County residents should be aware of West Nile virus and take some simple steps to protect themselves against mosquito bites,” Scott said. “The West Nile virus seems to be here to stay, so the best way to avoid the disease is to reduce exposure to and eliminate breeding grounds for mosquitoes.”

The Wisconsin Department of Health Services has monitored the spread of West Nile virus since 2001 among wild birds, horses, mosquitoes and people.

During 2002, the state documented its first human infections and 52 cases were reported that year.

In 2017, 39 cases of West Nile virus infection were reported among Wisconsin residents, resulting in four deaths. A total of 66 of the state’s 72 counties reported some kind of West Nile virus activity. Jefferson County had cases of the disease involving one bird, one horse and two humans that year.

There were no reports of West Nile virus in 2014. One bird in the county was reported in 2015 and two birds and a horse were reported in 2016.

To date this year, six human cases have been confirmed and 45 counties have reported activity.

Scott noted that mild cases would not be reported if the person was not tested.

“We are most worried about the serious cases, which, thankfully, are rare,” she said.

West Nile virus infections in humans have been primarily reported from June through October; however, most reported becoming ill with West Nile virus in August and September.

Prior to 2017, there had been no Jefferson County residents reporting the illness for two years, according to state records.

The majority of people, 80 percent, who are infected with West Nile virus do not get sick. Scott noted that those who do become ill usually experience mild symptoms such as fever, headache, muscle ache, rash and fatigue.

Fewer than 1 percent of people infected with the virus get seriously ill with symptoms that include high fever, muscle weakness, stiff neck, disorientation, mental confusion, tremors, paralysis and coma.

Older adults and those with compromised immune systems are at a greater risk of developing central nervous system illness that can be fatal.

Scott said the Jefferson County Health Department recommends the following:

• Limit time spent outside at dawn and dusk, when mosquitoes are most active, especially dawn and dusk.

• Wear long-sleeved shirts, long pants, socks, and shoes.

• Mosquitoes may bite through thin clothing, so spraying clothes with a repellent containing permethrin or DEET will give extra protection. These repellants are the most effective and most studied.

• Make sure window and door screens are in good repair to prevent mosquito entry.

• Properly dispose of items that hold water, such as tin cans, plastic containers, ceramic pots or discarded tires.

• Clean roof gutters and downspouts for drainage.

• Turn over wheelbarrows, wading pools, boats, and canoes when not in use.

• Change the water in birdbaths and pet dishes at least every three days.

• Clean and chlorinate swimming pools, outdoor saunas and hot tubs; drain water from pool covers.

• Trim tall grass, weeds, and vines since mosquitoes use these areas to rest during hot daylight hours.

• Landscape to prevent water from pooling in low-lying areas.

The Wisconsin Division of Public Health will continue surveillance for West Nile virus until the end of the mosquito season. To report a sick or dead crow, blue jay or raven, call 1-800-433-1610.For more information, contact the Jefferson County Health Department at: (920) 674-7275.