Developing Story Note: This report covers new developments in Florida's 2026 locally acquired dengue outbreak. State case figures come from the Florida Department of Health's Week 37 report, with data through Sept. 19, 2026. Hillsborough County declared a state of local emergency on Sept. 24. Numbers may change as the state releases more weekly reports and completes case investigations.
Florida reported 38 new cases of locally acquired dengue in its latest weekly surveillance report, bringing the state's 2026 total to 190. The cases span six counties, and 30 of them began in September, according to the Florida Department of Health's Week 37 arbovirus report, which covers Sept. 13 to 19.
Locally acquired means the person was infected by a mosquito in Florida, not while traveling. That distinction matters for anyone who gets sick without a recent trip, because neither the patient nor a clinician may think of dengue unless someone raises the possibility.
Hillsborough County accounts for 170 of the 190 cases, or nearly nine in 10. The September onsets show that transmission did not stop in August, so households in affected counties still have reason to watch for fever and mention possible mosquito exposure when they seek care.
Transmission Continued Into September
The state counted 170 cases in Hillsborough, seven each in Miami-Dade and Pinellas, three in Orange, two in Pasco, and one in Palm Beach. By the date symptoms started, 21 cases began in July, 139 in August, and 30 so far in September.
The September count is likely to rise. Symptoms start before a person is tested and the case is reported, so illnesses that began in late September may not appear until later reports.
The report also counted 17 mosquito pools, or batches of trapped mosquitoes, that tested positive this year. "In 2026, 190 cases of locally acquired dengue and 17 mosquito pools have been reported from six counties," the department wrote.
Dengue is caused by four related virus types. Of the 171 cases that were typed, 169 were DENV-2, and two were DENV-3. The state also reported 212 travel-associated dengue cases this year, up from 186 in the prior report, plus one locally acquired chikungunya case in Miami-Dade with onset in August. Duval, Hillsborough, Miami-Dade, Orange, and Pinellas counties are under mosquito-borne illness alerts.
Illness Without Travel History
Dengue spreads mainly through the bite of an infected Aedes mosquito. It does not spread through ordinary contact between people.
Because dengue cases diagnosed in Florida are usually linked to travel, a fever in someone who has not left the state may not immediately suggest dengue. Kristi Miley, a researcher at the University of South Florida's Center for Global Health Infectious Disease Research, told Newsweek that "The Bay Area has seen more locally acquired cases than in previous years, indicating a localized outbreak in Hillsborough County's mosquito population rather than a statewide increase." She added that Hillsborough "has not recorded this level of dengue infection since the 1930s."
"Many people may not seek care and fully recover without incidence; however it can be life-threatening for some, "Miley said. The CDC estimates that only about one in four people infected with dengue get sick, so official counts likely understate how many people have been infected. That is why telling a clinician about mosquito bites or living in an affected county matters, even without travel.
Common symptoms include fever with aches and pains, such as pain behind the eyes or muscle, joint, or bone pain, along with nausea, vomiting, or rash. Symptoms typically last two to seven days, according to the CDC's dengue symptoms page. About one in 20 people who get sick develop severe dengue, a medical emergency.
Warning Signs After the Fever Breaks
Warning signs of severe dengue usually begin in the 24 to 48 hours after a fever goes away, when people may assume they are recovering. The CDC lists belly pain or tenderness, vomiting at least three times in 24 hours, bleeding from the nose or gums, vomiting blood or blood in the stool, and feeling extremely tired or restless as signs that require emergency care.
Medication choices also matter. The CDC's dengue treatment guidance advises taking acetaminophen for fever and pain and warns, "Do not take aspirin or ibuprofen!" Those drugs can raise the risk of bleeding.
According to a CDC health advisory, people at higher risk of severe dengue include infants, pregnant women, adults 65 and older, people with certain medical conditions, and people who have had a previous dengue infection and get infected again.
Emergency Declaration Follows Weeks of Growth
MedicalDaily previously reported that Florida's local dengue count had reached 152, with Tampa Bay accounting for nearly all infections and 41 new cases in the prior week, the largest weekly increase this year.
The newest data mark the third straight week with at least 38 new local cases, following 38 in Week 35 and 41 in Week 36. Hillsborough rose from 134 to 170 cases. Newsweek, citing the Tampa Bay Times, reported that an 80-year-old Hillsborough County woman died of dengue complications on Sept. 4, the state's first dengue death of 2026. The Florida Department of Health later confirmed the death.
On Sept. 24, Hillsborough County Administrator Bonnie Wise signed an order declaring a state of local emergency over dengue. The order lasts seven days unless it is extended or rescinded, and it lets officials act quickly and seek federal reimbursement for certain costs. The county is conducting aerial mosquito treatments in several neighborhoods. Pasco and Pinellas counties declared their own local states of emergency the same week, and the Florida Department of Health in Polk County announced the county's first locally acquired case on Sept. 24. That case is not included in the Week 37 count.
Practical protection has not changed. Residents should empty and scrub, turn over, cover, or throw out items that hold water, such as flowerpot saucers, buckets, pet bowls, toys, and tarps, at least once a week. They should also use EPA-registered insect repellent and keep window screens in good repair.
The state releases arbovirus reports weekly, and the next update will show whether September cases keep climbing. For now, a fever after mosquito bites in an affected county is reason to call a clinician and mention dengue, whether or not the person has traveled.
Key Questions Answered
How many locally acquired dengue cases has Florida reported in 2026? There were 190 as of the Week 37 report, with data through Sept. 19, including 38 new cases that week.
What does locally acquired mean? The person was infected by a mosquito in Florida rather than while traveling outside the state or country.
Which counties have local cases? Hillsborough (170), Miami-Dade (7), Pinellas (7), Orange (3), Pasco (2), and Palm Beach (1).
Is dengue still spreading? Yes. Thirty cases had September onset dates, and that number may rise as reports catch up. Polk County also announced its first local case on Sept. 24.
What warning signs need emergency care? Belly pain, repeated vomiting, bleeding from the nose or gums, blood in vomit or stool, or extreme tiredness or restlessness, especially in the day or two after the fever fades.
Which pain relievers should people avoid? The CDC advises acetaminophen and warns against aspirin and ibuprofen, which can increase bleeding risk.
Published by Medicaldaily.com
