The three to five inches of rain that triggered flash flood emergencies across Franklin County on Aug. 20, left behind more than waterlogged basements and closed schools. It left standing water. Now the mosquitoes are hatching.
Franklin County Public Health's Mosquito Management Program has been deploying crews every day since the storm, applying a larvicide called BTI to pools of standing water across the county, according to NBC4. The agency also runs 150 traps weekly, collecting specimens that are sorted in a lab and tested for West Nile virus. Columbus Mayor Andrew Ginther said the storm dropped three to five inches of rain on the region.
The flooding introduced a particular concern: floodwater mosquitoes, a species whose eggs sit dormant in soil until inundation triggers them to hatch. Zach Holbert-Watson of Franklin County Public Health called them "very aggressive daytime biters," meaning residents doing yard cleanup are especially exposed.
West Nile already active locally
The New Albany and Plain Township area entered the flood with West Nile virus already circulating. Franklin County Public Health sprayed the area three times this summer after positive trap results: July 23, July 30 and Aug. 6. The city of New Albany announced each spray on social media, directing residents to the county's spray schedule and maps.
Holbert-Watson told NBC4 that mosquito abundance is tied to infection rates, which is tied to the risk of disease exposure. West Nile virus remains the leading cause of mosquito-borne disease in the continental United States, with no vaccine or specific treatment available.
What residents should do
Gahanna-Jefferson schools canceled classes on Aug. 20, and the city closed all parks and trails on Aug. 21 as cleanup continued. For residents still dealing with standing water in yards, ditches or containers, Franklin County Public Health recommends eliminating any sources of standing water around the home and wearing long sleeves and bug repellent when working outdoors.
Residents who cannot eliminate standing water on their own can call Franklin County Public Health's BITE line at (614) 525-2483. The county will send a crew to treat the site.
No post-flood spray schedule specific to Gahanna or New Albany has been announced. Residents can check for updates at mosquito.myfcph.org/spray-schedule-maps/.
