Eight Local Dengue Cases in Two Weeks: Hillsborough Sprays Tampa Heights as Alert Holds

The Florida Department of Health in Hillsborough County confirmed an eighth locally acquired case of dengue fever on Aug. 12, keeping the entire county under a mosquito-borne illness alert as students head back to class. All eight cases turned up inside the previous two weeks. Between 2010 and 2025, Hillsborough recorded nine local cases total.

That is the number that has mosquito crews working nights. Locally acquired means nobody flew home with it: the person was bitten here, by a mosquito carrying the virus here.

One trapped mosquito came back positive

Hillsborough County Mosquito Management runs BG traps across the county, baited with carbon dioxide and a scent that mimics a human. Trapped mosquitoes go to a lab, where the females are separated out and tested. One Hillsborough mosquito has already tested positive for dengue.

Gabriela Henderson, community relations coordinator for county Mosquito Management, said the real change this year is that the virus is circulating in the county's mosquito population, not just arriving in travelers. County officials said the positive trap result came in early last week, and that Hillsborough has only had a comparable detection once before, in 2008, with West Nile virus.

According to local news reports, a Mosquito Management supervisor said the confirmed cases are clustered near the I-4 and I-275 interchange, a dense stretch of neighborhoods close to Ybor City and Armature Works, and that the affected area is small and contained for now but could widen.

Where the helicopter flew

The spray schedule tracks that cluster. On Thursday, Aug. 13, the county flew an aerial application of Dibrom insecticide over Tampa Heights and Seminole Heights between 8:40 p.m. and midnight, by helicopter, at an altitude of 150 feet and a rate of .66 ounces per acre. The treatment block ran from Hillsborough Avenue south to the I-275/I-4 corridor, and from 22nd Street west to North Boulevard. Aug. 14 and Aug. 15 were listed as backup dates in case of weather.

Trucks are working the same neighborhoods at ground level, and technicians are knocking on doors to hand-treat yards, ditches and containers where the larvae live. The county's mosquito spraying map shows both planned treatments and anything sprayed in the past 28 days, so residents can check whether their own block has been covered. Hillsborough does not spray the same area more than once in a 28-day window.

A bottle cap of water is enough

Dengue is carried here by Aedes aegypti and Aedes albopictus. These are not the dusk mosquitoes most people plan around. They bite during the day, they stay low to the ground, and they go for ankles. They also breed close to houses in whatever holds rain: buckets, kids' toys left in the yard, tarps, saucers under planters, and especially old tires. Henderson said any container holding even a bottle cap's worth of water can support a full life cycle.

Once a week, walk the yard and dump anything holding water. Turn it over so it stays empty. Repair torn window and porch screens. Use an EPA-registered repellent with DEET, picaridin, IR3535 or oil of lemon eucalyptus, and wear long, loose, light-colored clothing when you are outside during the day.

What symptoms look like

Dengue shows up within 15 days of an infected bite. It usually reads as a hard flu without the respiratory part: fever, severe muscle and joint pain (the illness is nicknamed bone-break fever), pain behind the eyes, nausea, vomiting and sometimes a rash. It does not pass person to person. It spreads when a mosquito bites someone infected and then bites someone else.

Anyone with those symptoms is asked to call DOH-Hillsborough at 813-307-8010. Mosquito Management takes inspection requests and mosquito complaints at (813) 635-5400.

The alert stays in place until health officials lift it, and the count could move again: because symptoms lag a bite by up to two weeks, cases confirmed later this month may reflect bites that already happened. Residents can sign up through the county to be emailed before the next nighttime spray in their neighborhood.

Stay with Tampa Community Website for updates as the case count and spray zones change, and follow us on Facebook for alerts as they post. Seeing more daytime biters on your street than usual? Join the conversation in our Community Forum. You can also read more healthcare stories and local alerts from around Hillsborough County.

Header photo: James Gathany / Wikimedia Commons (Public domain)