Louisville’s Department of Public Health and Wellness reported mosquitoes carrying West Nile virus were found in four local ZIP codes.
The mosquitoes were found in surveillance traps in 40205, 40212, 40214 and 40215.
“West Nile infected mosquitoes are not unusual for this time of year,” Connie Mendel, assistant director of Louisville’s health department, said in a statement.
People with West Nile usually have no symptoms or very mild ones. Symptoms include fever, diarrhea, vomiting and rashes. Less than 1 percent of those infected will experience severe symptoms affecting the nervous system, and such reactions typically only occur in people who are older or have pre-existing conditions.
Officials say people can still enjoy the outdoors but should take precautions, such as using insect spray and covering their legs and arms, particularly during peak mosquito hours around dawn and dusk.
The Department of Public Health and Wellness will be fogging the affected areas — Churchill Downs, Portland, the Highlands and Iroquois — Thursday morning and evening. The department uses the insecticide Zenivex, which officials say has a low toxicity and burns off quickly in the sun. There has been no guidance for people to change their usual routine in response to the fogging.
Fogging is a regular part of the city’s attempts to prevent mosquito-borne illness: In the spring they fog to prevent eggs from hatching. During the summer, fogging takes place regularly.
There have been no human cases of West Nile reported this year or last in Louisville. The last reported cases took place in 2019, when there were two cases, one of which was fatal.
More information about West Nile-infected mosquitoes reported in Louisville can be found on the Department of Public Health and Wellness website.