Florida health officials report 10 locally acquired dengue fever cases this year, marking the first time in 15 years the virus has spread locally in Pinellas County. Hillsborough County also recorded eight cases in two weeks, prompting the Florida Department of Health in Pinellas County to issue an official mosquito-borne illness alert.
Local Transmission Returns to Pinellas and Hillsborough Counties
A mosquito-borne illness rarely seen spreading locally in Florida has returned after more than a decade. State health authorities have confirmed 10 locally acquired cases of dengue fever across Florida so far this year. The total includes eight cases concentrated in Hillsborough County and two in Pinellas County.
While the state frequently records travel-associated cases from individuals bitten abroad, local spread represents a notable shift in vector-borne disease activity. In Pinellas County, this marks the first instance of local transmission in 15 years. The U.S. Centers for Disease Control notes that national travel-related totals have reached 1,471 cases this year. Health officials explain that an infected traveler likely brought the virus home before being bitten by local mosquitoes, which then perpetuated the cycle.
“Pinellas doesn’t have any modern history of having dengue in the county,” Alyssa Berro, the county’s mosquito control manager, told WUSF. “So this is one of those cases [where] somebody has returned from somewhere they got bit. And then got bit by our mosquitoes, which then started the transmission in this area.”
Alyssa Berro, the county’s mosquito control manager
Targeted Interventions and Daytime Fogging in Palm Harbor
Following the health department alert, Pinellas County Mosquito Control scaled up suppression efforts specifically around the Palm Harbor area. Crews deployed increased ground inspections and initiated dawn truck-mounted fogging after monitoring data revealed elevated mosquito populations and virus activity.
Unlike other mosquito species, the primary vectors for dengue—Aedes aegypti and Aedes albopictus—are daytime biters that breed in small containers on private property. Because of this behavior, traditional aerial larviciding and standard adulticide treatments prove ineffective against them. County teams are conducting door-to-door inspections, daytime backpack fogging, and daily surveillance, urging property owners to grant technicians access to eliminate overlooked breeding sites.
Why Container Breeding Complicates Vector Control
The biological habits of Aedes aegypti and Aedes albopictus
make eradication uniquely challenging for municipal crews. These insects thrive in residential environments, laying eggs in common items left outdoors during rain events.
Broader Surveillance Across Pinellas County
Dengue is colloquially known as breakbone fever
due to the severe muscle and joint pains it can cause. According to federal health data, about 25% of individuals bitten by an infected mosquito develop symptoms, which range from fever and rash to debilitating body aches. Treatment generally centers on rest, fluids, and acetaminophen.
Simultaneously, county staff have observed an uptick in West Nile virus activity among sentinel chickens, which serve as early warning indicators for West Nile, St. Louis, and Eastern Equine Encephalitis. While no human cases of West Nile have been reported in Pinellas County this year, the finding triggered enhanced overnight truck treatments and daytime aerial applications to suppress broader virus transmission.
How Residents Can Protect Against Mosquito-Borne Illnesses
With daytime-biting mosquitoes active across private property, municipal officials emphasize that community cooperation is essential.
- Dump: Eliminate or cover any standing water around property, including debris from recent storms.
- Dress: Wear light-colored, long-sleeved shirts, long pants, and closed-toed shoes.
- Defend: Apply insect repellent containing CDC-recommended ingredients such as DEET, Picaridin, IR3535, or Oil of Lemon Eucalyptus.
Residents can review interactive treatment maps online to check scheduled county operations. Anyone experiencing potential symptoms of a mosquito-borne illness is instructed to contact the Florida Department of Health in Pinellas County directly at (727) 824-6932.
