Dengue Outbreak Forces Three Florida Counties to Declare Emergencies, One Death Confirmed in Hillsborough

Since the Florida Department of Health confirmed on September 18 that an elderly Hillsborough County woman who died September 4 had dengue fever, the outbreak has grown large enough to trigger emergency declarations in three Tampa Bay counties within the same week.

Hillsborough County Administrator Bonnie Wise signed an executive order September 24, effective the next day, declaring a state of local emergency under Chapter 252 of Florida Statutes and the county's Emergency Management Ordinance, according to Hillsborough County's own release. Pasco County declared its emergency September 23. Pinellas County commissioners followed September 24, citing authority under Florida Statutes section 252.38(3)(b)5 and the Pinellas County Charter, according to Pinellas County government and NTD.

Case counts vary across reports

Pinellas County's official government release, dated September 24 and citing the Florida Department of Health's latest report, put the Tampa Bay region's confirmed case count at 179 across the three counties, with seven of those in Pinellas itself.

But NTD, reporting the same day, broke the total down as 134 confirmed cases in Hillsborough, seven in Pinellas and two in Pasco, plus one death and 21 additional suspected cases under investigation, including some tied to workplace exposure. Add those three county figures and you get 143, not 179. Ground News, aggregating coverage from the same window, cited 190 cases statewide with Hillsborough at 170.

The Daily Mail, drawing on CDC and Florida Department of Health figures, reported yet another set: 160 cases in Hillsborough, seven in Pinellas, two in Pasco, with 38 new local cases recorded in a single week. The same Daily Mail report cited CDC data showing Florida had 392 total dengue cases this year, 183 of them locally acquired, versus just 72 local cases last year. The discrepancies across these tallies likely reflect different reporting dates and revision cycles between county health departments and the state, but no single source in this reporting reconciles the gap. The trajectory, regardless of which count you use, points upward. Case numbers have climbed sharply from 2025.

A national pattern, not just a Florida problem

The Daily Mail also cited a CDC report showing a 359% jump in average annual U.S. dengue cases in 2024 compared with the 2010-2023 average, with a record 3,798 cases reported in 2024 nationwide. Ninety-seven percent of those were travel-associated; the remaining 105 were locally acquired. Six people died. The CDC separately reported one locally acquired case this year in Virginia, outside Florida entirely, per the Daily Mail.

Dengue is transmitted by Aedes aegypti mosquitoes that bite during the day and can breed in an amount of standing water as small as a bottle cap, according to an infectious disease physician writing for The Conversation and republished by CNN. The physician noted that roughly three in four infections cause no symptoms at all, but about one in 20 symptomatic patients progress to severe dengue, a life-threatening complication that often strikes just as the initial fever breaks. The Daily Mail cited a slightly different range, saying 40 to 80 percent of infections are asymptomatic.

Pinellas County's release added a detail not covered elsewhere in this outbreak: mosquito surveillance through sentinel chicken coops has also picked up increased West Nile virus activity, which officials called an early warning sign for potential human transmission separate from the dengue cluster.

Emergency declarations and response measures

All three county declarations authorize emergency spending on mosquito control without normal budget approval steps and open the door to state or federal reimbursement if Governor Ron DeSantis's administration makes funding available, according to Hillsborough County and Pinellas County government releases.

Uniformed Pinellas County mosquito control staff wearing ID badges are going door to door near treatment zones, asking residents' permission to inspect properties for breeding sites, per the county's own release. Officials in all three counties are urging residents to dump standing water weekly, from flowerpots and gutters to pet bowls and pool covers, wear long sleeves and closed-toe shoes, and use EPA-registered repellents containing DEET, Picaridin, IR3535 or oil of lemon eucalyptus.

Under Florida law, a local state of emergency lasts seven days unless county officials vote to extend or rescind it. Hillsborough's order, effective September 25, and Pinellas's, effective September 24, are both set to lapse around October 1 absent a renewal vote. Anyone suspecting a mosquito-borne illness in Pinellas County is directed to call the Florida Department of Health's local office at (727) 824-6932. Whether Hillsborough, Pinellas and Pasco extend their declarations past the seven-day window will depend on whether the Florida Department of Health's next case update, expected in the coming days, shows the outbreak still climbing.