Marion County has transitioned from high risk of West Nile virus transmission in early June to low risk, according to the most recent Kansas Department of Health and Environment risk report.
West Nile virus is the most common mosquito-borne illness in Kansas and the United States, according to the KDHE website.
Physician Alisa Schmidt, who treats patients at the Hillsboro Clinic, said she has seen a slight increase in mosquito bites this year.
“Mosquito bites and chigger bites have been slightly worse than normal,” she said.
The risk of West Nile virus transmission is lower in the spring but rises during the summer months, peaking during July, August and September.
The Culex species of mosquito is specifically known to transmit the virus.
To determine transmission risk levels state-wide, each week this summer from mid-May through mid-October, the KDHE has collected data from mosquito surveillance in Sedgwick, Reno and Shawnee counties.
Risk level is determined based on the presence of the Culex species, human cases of the virus reported to the KDHE, increase in the number of Culex mosquitos and historical data indicators for the weeks of increased human cases.
A number of factors affect the risk of infection, including time of year, number and location of infected Culex mosquitoes and amount of days with sufficient heat.
The KDHE releases the Kansas West Nile Virus Weekly Surveillance and Transmission Risk Report, which monitors the transmission risk level of the West Nile virus in three regions: west, central and east.
Marion County is on the eastern edge of the central region.
According to the KDHE, risk level has decreased from high to low for the central and west regions and from high to moderate for the east region. In early June, all three regions were at high risk.
In areas of low risk, the Culex species has been detected but infection is unlikely, while in moderate risk areas, high numbers of mosquitoes that carry the virus have been detected, and infection is likely or may have already happened.
In high risk areas, mosquitoes have tested positive for the virus, or historical human cases have provided a basis for a higher risk level for the week. In these areas, many people may be infected with the virus.
No West Nile virus positive mosquitoes were identified during the week ending July 28, according to the report, which also stated that one West Nile Virus human case investigation was in progress and no additional human cases were identified.
As of July 21, four human cases of West Nile virus have been reported in Kansas, two in Barton County, and one each in Barber and Osborne counties, according to KDHE.
In 2016, 34 cases of West Nile virus were identified in Kansas.
To protect against West Nile virus, KDHE recommends the following:
• When you are outdoors, use insect repellent containing an EPA-registered active ingredient on skin and clothing, including DEET, picaridin, oil of lemon eucalyptus or IR3535. Follow the directions on the package.
• Many mosquitoes are most active at dusk and dawn. Be sure to use insect repellent and wear long sleeves and pants at these times, or consider staying indoors during these hours.
• The elderly or immuno-compromised should consider limiting their exposure outside during dusk and dawn when the Culex species mosquitos are most active.
• Make sure you have good screens on your windows and doors to keep mosquitoes out.
• Get rid of mosquito breeding sites by emptying standing water from flower pots, buckets and barrels. Change the water in pet dishes and replace the water in bird baths weekly. Drill holes in tire swings so water drains out. Keep children’s wading pools empty and on their sides when they are not being used.