Florida's Tampa Bay logs its largest local dengue outbreak in years, with one death
Surveillance data show 252 locally acquired dengue cases in the Tampa Bay area by 26 September, 223 of them in Hillsborough County, where an 80-year-old woman has died. Three counties have declared emergencies.
| Group | Value (value) |
|---|---|
| Hillsborough | 223 |
| Pinellas | 13 |
| Pasco | 3 |
A locally transmitted dengue outbreak on Florida's west coast is the largest the Tampa Bay area has seen in years and is still growing, according to surveillance data from the Florida Department of Health reported by The BMJ on 5 October 2026 [s1]. By 26 September the outbreak had reached 252 locally acquired cases across the Tampa Bay area, with the first case of the year logged in Hillsborough County in July [s1][s2].
"Locally acquired" is the phrase that matters. Most dengue cases recorded in the continental United States are imported by travellers; autochthonous transmission, where the virus is passed between local mosquitoes and people who have not left the area, is far less common and is what turns scattered cases into an outbreak.
Where the cases are
Hillsborough County, which contains the city of Tampa, is the centre of it, with 223 locally acquired cases this year — up from a single case in 2025 [s1]. One death has been reported: an 80-year-old woman died of dengue, septic shock and multi-organ failure at Tampa General Hospital [s1].
Three counties in the Tampa Bay area — Hillsborough, Pinellas and Pasco — have declared ongoing public health emergencies [s1]. Pinellas has reported 13 locally acquired cases so far this year and Pasco three [s1]. The declarations let the counties speed up spending on the response, including mosquito control [s1].
The reported case count almost certainly understates the true number of infections. The US Centers for Disease Control and Prevention estimates that only about one in four people infected with dengue develop symptoms, so most infections never reach a clinician or a surveillance report [s1]. Surveillance of the mosquitoes tells a parallel story: 20 mosquito pools — groups of insects collected in a single trap — have tested positive for dengue virus, 19 in Hillsborough County and one in Pasco [s1].
The disease
Dengue is spread by the bite of infected Aedes aegypti and Aedes albopictus mosquitoes, both of which are established in Florida [s1]. Symptoms begin three to 14 days after a bite and include sudden fever, severe headache, pain behind the eyes, and the muscle and joint pain that give the illness its nickname, "breakbone fever"; the fever typically lasts four to seven days [s1].
There are four dengue virus serotypes, and about three-quarters of infections cause no symptoms [s1]. The complication that makes dengue dangerous is severe disease, which is more likely after a second infection with a different serotype: warning signs include severe abdominal pain, persistent vomiting, and bleeding from the nose or gums or in vomit or stool [s1]. There is no dengue vaccine available in the United States, and no specific antiviral treatment; the Florida Department of Health notes that quick recognition and management of symptoms and complications is what prevents deaths [s1].
Why it is happening now
Autochthonous dengue in Florida tracks the warm, wet months that let Aedes mosquitoes breed, and the state has recorded small local clusters in recent years. What distinguishes 2026 is scale: a jump from one case in Hillsborough in 2025 to 223 this year is a step change, not seasonal noise, and the continuing spread through late September is why the emergency declarations went out. The CDC's one-in-four symptomatic estimate means the true extent of local transmission is wider than the official tally.
What to watch
Two things will show whether the outbreak is turning. The first is the weekly locally acquired case count in the Florida arbovirus reports — whether new cases slow as mosquito-control measures and cooler autumn weather take hold [s2]. The second is geographic spread beyond the three counties now under emergency declarations; additional counties reporting their own locally acquired cases would signal that transmission is no longer contained to the Tampa Bay core. Residents in affected areas are advised to use repellent, cover their arms and legs, and empty or cover standing water where mosquitoes breed [s1].
Sources
- Dengue: Woman dies in Florida's largest outbreak in years — The BMJ, 5 October 2026
- Weekly arbovirus reports: Week 38, September 20–26 — Florida Department of Health, 26 September 2026
Sources
- Dengue: Woman dies in Florida's largest outbreak in years — The BMJ , October 5, 2026
- Weekly arbovirus reports: Week 38, September 20–26 — Florida Department of Health , September 26, 2026
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