LOUISVILLE, Ky. (WDRB) — The Louisville Metro Department of Public Health and Wellness is fogging areas of Fern Creek and near Churchill Downs after one person was diagnosed with West Nile virus in Louisville.
"Mosquito fog" is sprayed by city trucks. It is a synthetic pyrethrin approved by the Environmental Protection Agency.
"We do regular trapping weekly throughout Jefferson County," LMPHD Director Connie Mendel said. "If we reach a high number of mosquitoes in those traps, we fog to reduce those numbers to try to prevent transmission of West Nile or other mosquito-borne diseases."
The city also fogs an area if a resident tests positive for West Nile virus. The city posts scheduled fogging areas online.
"It will drive down the streets, in alleys, even back up maybe to a wooded area," Mendel said. "You'll see like a fog coming from the back of the truck, and usually you can hear them because the engine is like a large lawnmower engine."
The trucks begin mosquito fogging when it starts to get dark because that is when mosquitoes are most active.
"We just ask that folks not travel closely behind it. Try to park off the street if you can," Mendel said. "We definitely would encourage folks to go inside, and if you want to bring your pets in that's also a good idea."
The mist is biodegradable and will not leave residue in trees or grass, Mendel said. It only kills mosquitoes.
"The good thing about fogging is that it does kill adults (mosquitoes) on contact," Mendel said. "The thing that's not as helpful is it doesn't do anything to mosquito eggs."
Mosquito larvae are typically found in stagnant water, even in puddles as small as overflowed water in flower pots.
"Any water that stands for five days can breed mosquitoes," Mendel said. "And the hotter it is, the quicker they go through their life cycle and hatch off."
Mendel recommends getting rid of stagnant water near your house, such as in tires or on roofs.
She also suggests using mosquito repellent and wearing long sleeves to avoid getting bitten.
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