Dengue fever cases are escalating across Florida, prompting multiple counties to declare states of emergency. The state has recorded 497 cases this year, with 252—approximately 51%—transmitted locally via mosquitoes rather than brought in by travelers. In early September, the Florida Department of Health confirmed the state’s first dengue-related death in nearly 100 years.
Historically, Florida’s dengue cases were predominantly travel-associated. However, Caroline Waddell, a public health researcher at the University of Florida, noted that while the 245 travel-related cases this year are not anomalously high, locally acquired infections are more than five times higher than at any point in the previous four years.
The current outbreak is centered in Hillsborough County, north of the traditional hotspot in Miami. Hillsborough has accounted for 223 of the state’s 252 local cases and is where the fatal case occurred. Routine mosquito surveillance has detected dengue-positive samples in seven counties, with 19 positive pools coming from the greater Tampa area. By comparison, only four pools tested positive statewide in 2025, and just one in 2023.
“Finding positive mosquito pools is rare in Florida because dengue is not endemic to the state,” said Keira Lucas, deputy executive director of the Collier Mosquito Control District. She described the search as “like looking for a needle in a haystack” and warned that detecting positive pools likely indicates widespread community transmission, given that roughly 75% of infections are asymptomatic.
Experts attribute the surge to a combination of climatic and environmental factors. Dengue, transmitted by Aedes aegypti and Aedes albopictus mosquitoes, has seen global cases increase tenfold between 2000 and 2019. Rising temperatures expand the range of these vectors and accelerate viral replication. In Florida, a severe drought—described as the most intense in over a decade—may have inadvertently fueled mosquito populations. While droughts typically reduce standing water, increased residential sprinkler use creates puddles and fills containers that serve as breeding grounds for human-adapted Ae. aegypti. Additionally, dehydrated mosquitoes may bite more frequently in search of fluids.
Panpim Thongsripong, a disease ecologist at the University of Florida, called the situation an “unlucky combination” where conditions aligned perfectly for an outbreak. Neighboring Pasco and Pinellas counties have also declared local states of emergency.
Looking ahead, a strong El Niño pattern is expected to bring a rainier winter to Florida, potentially increasing mosquito numbers further. Waddell emphasized that the outbreak is not over, noting that new cases with September onsets are still being reported. Health officials urge residents to use repellent, eliminate standing water around homes, and support coordinated mosquito control efforts involving larvicide targeting.
Is the state really prepared for a hundred-year death? The emergency declarations feel too little, too late.
Residents need to stop ignoring standing water in their yards. It’s simple prevention that saves lives.
El Niño bringing more rain next winter? This is going to get much worse before it gets better.
I had no idea dengue could be this severe in Florida. The drought connection is really surprising.