Summer in Monroe County this year has been hot, humid and wet.
These conditions have created an ideal breeding ground for mosquitoes, said Matt Modjeski, a Department of Natural Resources conservation warden.
Modjeski said he hasn’t noticed a big difference in the number of mosquitoes, but said six to seven inches of excess rain the county has received this year has done nothing to hinder their abundance. Mosquitos lay and hatch their eggs in water and have been thriving during several years of above-average rainfall.
“I’m not a bug expert by any means, but this time of the year, meaning July and August, there’s always an abundance of mosquitoes and deer flies; it’s just that time of year,” he said.
Sharon Nelson, director of the Monroe County Health Department, said mosquitoes not only are a nuisance but also carry a health risk as they can carry disease.
There are two diseases county residents need to be aware of and protect themselves from Nelson said. They are La Crosse Encephalitis and West Nile Virus.
La Crosse Encephalitis affects the central nervous system, causing inflammation of the brain. It affects people of any age but usually children, Nelson said. The virus is a common disease in the United States and produces a fever, headache, drowsiness, vomiting and, in half the cases, convulsions.
Few die of the disease, Nelson said, but because of the severity of the symptoms, those who contract it are usually hospitalized.
The mosquito that spreads the virus “breeds in any object that holds water over a prolonged period ... including basal tree holes and old tires in particular” and are generally found in wooded areas.
Eliminating breeding sites is the most effective control method.
West Nile virus first appeared in the United States in 1999 in New York.
The first case in Wisconsin was in 2002, Nelson said, and the most recent case in Monroe County was in 2017.
About 80 percent of people infected by the disease never experience any symptoms, and those who do experience a mild fever, headache, muscle ache, skin rash, swollen lymph nodes and fatigue, Nelson said. Fewer than one percent of people infected become seriously ill.
Severe symptoms include a high fever, neck stiffness, extreme muscle weakness, tremors, convulsions or disorientation.
Eric Prise, marketing and public relations director at Tomah Memorial Hospital, said no cases of mosquito-borne illnesses have been reported at the hospital this year.
“We usually do not get any or many,” he said. “Occasionally we get a few, but this year has been a pretty normal summer in Tomah regarding mosquitoes.”
It’s important that the public “remain vigilant in protecting themselves against mosquitoes,” Nelson said.
To prevent or limit exposure to either disease, the Monroe County Health Department recommends that people use insect repellent, limit time spent outside, particularly around dawn when mosquitoes are most active, and make sure window and door screens are in good repair to prevent entry into homes.
The health department also recommends eliminating breeding sites by removing standing water.
For more information on how to eliminate standing water visit dhs.wisconsin.gov/environment/mosquito.htm or contact the Monroe County Health Department at 608-269-8666.