Hillsborough, Pinellas and Pasco counties have taken emergency action as officials intensify mosquito control against locally acquired dengue infections.
TAMPA, Fla. — Three Florida counties have declared local states of emergency as a dengue fever outbreak spreads through the Tampa Bay region, prompting intensified mosquito-control operations and growing concern over an unusually large number of locally acquired infections.
Hillsborough, Pinellas and Pasco counties issued emergency declarations in late September as officials worked to contain the mosquito-borne disease. Hillsborough County, the center of the regional outbreak, declared a state of local emergency Sept. 24. Pinellas County commissioners approved their declaration the same day, while neighboring Pasco County also took emergency action. The declarations are local measures rather than a statewide emergency declaration covering all of Florida.
Dengue is a viral illness transmitted primarily through the bite of an infected Aedes mosquito. Florida’s warm climate supports the mosquitoes capable of spreading the virus, but most dengue cases historically reported in the state have been associated with international travel. The scale of local transmission in 2026 has therefore drawn heightened attention from health and mosquito-control officials.
Florida health surveillance data showed 190 locally acquired dengue cases through Sept. 19, along with more than 200 travel-associated cases. Federal surveillance data listed 392 dengue cases among Florida residents as of late September, although federal and state figures can differ because of reporting schedules and the way cases are classified. The Centers for Disease Control and Prevention cautions that its current-year surveillance figures are provisional and subject to change.
The Tampa Bay region has been particularly affected. Pinellas County said the Florida Department of Health’s Sept. 24 report showed 179 confirmed cases across Pinellas, Pasco and Hillsborough counties. Seven were in Pinellas County. Hillsborough County accounted for most of the regional infections and has been treated as the center of the outbreak.
At least one death has been associated with the outbreak in Hillsborough County. Pinellas County’s emergency resolution cited the confirmed death while outlining the threat posed by the regional spread of dengue. Officials have continued surveillance as additional suspected infections are investigated and classified.
The emergency declarations give local governments greater flexibility to respond. Hillsborough County said its declaration allows emergency managers to act quickly to protect public health and provides a path for possible federal reimbursement of certain expenses. Pinellas County said its declaration allows the county administrator to rapidly approve mosquito-control spending and seek reimbursement if state funding becomes available.
Mosquito-control operations have intensified across affected communities. Hillsborough County has used aerial and ground treatments in areas where officials have detected dengue activity. Pinellas County has also increased surveillance, inspections and treatments, including efforts to identify mosquito breeding sites and reduce populations in areas where cases have been reported.
Most dengue infections cause no symptoms or relatively mild illness, but symptomatic patients can develop fever, severe headache, muscle and joint pain, nausea, vomiting or rash. Some infections progress to severe dengue, which can cause dangerous complications and require hospitalization. Health officials monitor suspected cases because infected people can contribute to local transmission when mosquitoes bite them and later bite other people.
Florida has experienced locally transmitted dengue before. State surveillance recorded 199 locally acquired cases in 2023, making that year an important comparison for the current outbreak. With 190 locally acquired infections already reported through Sept. 19, the 2026 total was approaching that earlier level before the end of mosquito season.
Officials in the affected counties continue mosquito surveillance and control operations while state health authorities track newly reported infections. Hillsborough County remained in an active dengue response, while Pinellas County remained under a mosquito-borne illness alert and local state of emergency as of late September.
Author note: Last updated September 29, 2026.