Florida battles largest dengue outbreak in decades as locally acquired cases reach 252

The Florida Department of Health’s (FDOH) Week 38 report listed 62 locally acquired cases to the state total, up from 190 in Week 37.

State reports and medical literature suggest Florida’s 2026 outbreak is the largest calendar-year total for any mainland U.S. state since at least the 1940s the Associated Press (AP) reported.

Hillsborough County accounted for 223 cases, or about 88% of the state total. FDOH mapped another 13 exposures to Pinellas County, eight to Miami-Dade, three each to Orange and Pasco, and one each to Palm Beach and Polk counties.

DENV-2 accounted for 230 of the 232 locally acquired cases serotyped by PCR; the other two were DENV-3. Twenty Aedes aegypti mosquito pools had tested positive for DENV-2, including 19 in Hillsborough County and one in Pasco County.

FDOH also recorded 245 travel-associated dengue cases through September 26, including 201 associated with travel to Cuba. Locally acquired cases therefore slightly exceeded travel-associated cases in the state report.

Florida recorded 62 locally acquired dengue cases in all of 2025. The 252 cases reported through September 26, 2026, are 190 more than that total—an increase of approximately 306%, or just over four times the 2025 count.

FDOH confirmed the first dengue-related death of 2026 on September 18. The Tampa Bay Times reported that an 80-year-old Hillsborough County woman died at Tampa General Hospital on September 4 and that her death certificate listed dengue infection, septic shock and multi-organ failure.

Hillsborough, Pinellas and Pasco counties declared local emergencies in late September to support mosquito-control operations. Hillsborough and Pinellas extended their orders through October 8, while Pasco’s original September 23 declaration was issued for seven days.

Hillsborough scheduled nighttime helicopter applications of Dibrom adulticide over the Temple Terrace/University area and communities from Thonotosassa to Bloomingdale from 19:30 EDT (23:30 UTC) on October 7 to 06:00 EDT (10:00 UTC) on October 8.

The mission, supported by Manatee County Mosquito Control District, was to be flown at approximately 46 m (150 feet) with an application rate of about 48 mL/ha (0.66 fluid ounces per acre).

Separate daytime flights from October 5–9 were applying liquid Bacillus thuringiensis israelensis (Bti) to standing water in East Lake/East Tampa and Palm River/West Bloomingdale to target mosquito larvae. Hillsborough said Lee County Mosquito Control District was helping with contractors for that operation.

The county said mosquito traps in multiple neighborhoods continued to show dengue virus activity. Officials urged residents to use EPA-registered insect repellent, cover exposed skin, empty or cover standing water and properly dispose of discarded tires.

CDC says mosquitoes that spread dengue can bite during the day and night. Residents and visitors should use repellent, wear loose-fitting long sleeves and trousers, maintain window and door screens or use air conditioning where possible, and remove standing water around homes.

Dengue commonly causes fever with aches, nausea, vomiting or rash. CDC says about one in four infected people become ill and about one in 20 people who become ill develop severe dengue, which can cause shock, internal bleeding and death.

FDOH says symptoms can appear 3–14 days after the bite of an infected mosquito. CDC says there is no specific medicine for dengue and advises people with fever or other symptoms to contact a healthcare provider; warning signs of severe dengue require immediate medical care.

References:

¹ Florida Arbovirus Surveillance, Week 38: September 20–26, 2026 – FDOH

² Florida’s dengue outbreak is now the largest in the continental U.S. in decades – AP – October 2, 2026

³ Hillsborough County and partners treating for mosquitoes by air Wednesday night – Hillsborough County – October 7, 2026