TAMPA, October 8 — Three counties around Tampa Bay have extended local states of emergency into October after Florida recorded 252 cases of dengue acquired inside the state, the largest such outbreak in the continental United States in decades.
The state health department count, published through September 26, places 223 of those infections in Hillsborough County, which includes Tampa — about 89 percent of the Florida total. Pinellas and Pasco counties account for most of the remainder, and Broward County confirmed its first local case of the year on October 5, becoming the eighth Florida county to report local transmission in 2026. One death has been recorded: an 80-year-old Tampa woman bitten near her home in early September.
The comparison with recent years is stark. Florida logged 62 locally acquired cases in 2025, and its previous high was just under 200 in 2023. Nationally, 2024 was a record year for dengue in the United States, yet 97 percent of those cases were travel-associated and only 105 were acquired locally across three states.
Health officials attribute the scale to a change in what arrived rather than how much. Florida counted 245 travel-associated cases through late September, up about 11 percent from a year earlier, but the origin and the serotype shifted: 201 of those infections were linked to travel to Cuba, and imported cases carrying the DENV-2 serotype rose roughly eightfold, from 22 to 183. Of 232 locally typed cases this year, 230 were DENV-2. Cuba’s own epidemic has run well above normal while fuel shortages have curtailed fumigation on the island, and daily flights link the two.
Containment has been expensive and, in part, unusual. The emergency declarations rest on Chapter 252 of the Florida Statutes, the law counties invoke before hurricanes, suspending ordinary rules for contracts and hiring. They also authorise mosquito-control crews to enter public and private property during daylight and to remove standing water without prior notice — powers that matter against Aedes aegypti, which breeds in flowerpot saucers, buckets and tires within metres of homes and bites mainly by day, when aerial and truck spraying reach it least effectively. Hillsborough has approved emergency mosquito-control purchases above $848,000 and is seeking total spending of up to $1 million; Lee County’s mosquito district has spent about $250,000 on insecticide alone.
Officials are watching for a peak. Hillsborough mosquito managers said recently collected traps had tested negative and that case arrivals were beginning to slow, while warning that pressure on the vector must be maintained. New state surveillance data covering September 27 to October 3 were expected this week.
Researchers frame the episode as the product of a regional transmission system rather than a local failure. Genomic analysis published as a preprint in May by Yale University and the Florida Department of Health, covering 2010 to 2024, found that Florida outbreaks generally arise from frequent, short-lived introductions from the Caribbean rather than from lineages surviving year to year. Cooler nights expected in November normally suppress transmission; the last documented winter survival of dengue in Florida was in Key West in 2009 and 2010.
Dengue spreads through infected Aedes mosquitoes and most infections are mild, but the US Centers for Disease Control and Prevention estimates that about one in 20 symptomatic patients develops severe dengue, with warning signs often appearing as fever subsides.