The state has seen 497 reported cases so far this year. Of those, 252, or about 51%, were caught locally, rather than brought to the state by travelers. The Florida Department of Health confirmed one woman's death from dengue fever in early September, marking the state's first known dengue death in almost a century.
Why are local dengue cases especially high this year? Live Science spoke with experts to find out.
Mosquitoes capable of carrying dengue pick up the virus from people and then spread it to additional people via their bites. (Image credit: Centers for Disease Control and Prevention)
About 100 million to 400 million dengue infections happen annually worldwide, with about 800 cases reported in the U.S. historically, although that number has increased recently. Only about 1 in 4 people exposed to the dengue virus develop symptoms, which can include fever, headache, body aches, nausea and rash. About 1 in 20 cases become severe, and immunocompromised people, children, older adults and pregnant people are especially susceptible to these serious infections.
Dengue has escalated as a global health concern in the past few decades. Between 2000 and 2019, global cases of dengue increased tenfold; between 1990 and 2021, dengue-related deaths doubled. Scientists say this surge is likely driven by climate change, since rising temperatures expand Ae. aegypti mosquitoes' range, in turn exposing more people to the insects' bites. Plus, warmer conditions speed up mosquitoes' life cycles and the dengue virus's replication rate, thereby boosting transmission.
Zooming in on Florida
As the global picture has worsened, dengue cases in the U.S. have also increased.
Since approximately 75% of dengue infections are asymptomatic, the virus can circulate within a community without being readily detected for some time.
Each year, Florida experiences dengue outbreaks in the southernmost parts of the state, such as Miami and the Florida Keys, Panpim Thongsripong, a disease ecologist at the University of Florida, told Live Science. Historically, outbreaks in Miami typically totaled around 50 or fewer cases. But then a 2019 outbreak resulted in over 200 cases, and from 2022 to 2024, outbreak totals have ranged from about 500 to 675 cases.
Florida's health department regularly traps mosquitoes and tests them for viruses. So far this year, 20 pools of mosquitoes have tested positive for dengue across seven counties, and 19 of those positive pools were sampled from the greater Tampa area. In 2025, only four mosquito pools throughout the state tested positive, and in 2023, one mosquito pool did.
Routine mosquito trapping is a relatively inefficient method for detecting viruses, though, Lucas said. As such, detecting dengue-positive mosquito pools may indicate that a large amount of transmission is already unfolding. "Since approximately 75% of dengue infections are asymptomatic, the virus can circulate within a community without being readily detected for some time," Lucas explained.
So what's driving the unusual dengue activity this year?
For the virus to persist in local mosquitoes, dengue still needs to be reintroduced periodically through travel-related cases. Because the virus is not yet endemic to the state, it doesn't regularly circulate in local mosquitoes; however, a somewhat predictable "dengue season" has been emerging that coincides with upticks in international travelers carrying the virus to Florida.
The dengue virus is a member of the Flaviviridae family, meaning it's closely related to the Zika virus and yellow fever virus. (Image credit: koto_feja via Getty Images)This year, Florida has also been enduring its most intense drought in over a decade. In theory, that might be expected to limit mosquito populations because the pests need water to breed, Lucas said. However, when it's dry, people tend to run their sprinklers more, creating mosquito breeding grounds when puddles form or containers fill up, she noted. This could bring mosquitoes closer to people, as it creates opportunities for them to breed.
"It's almost like an unlucky [combination]," Thongsripong said. "Everything coming together at the right time and right place, and boom, you have the conditions for an outbreak to occur."
What can be done
It's too early to definitively say what factors have increased Florida's dengue cases this year, Thongsripong said, as scientists are still gathering information. Despite the unknowns, she thinks the health and housing infrastructure in the U.S. will stop dengue from becoming too dangerous here.
Exclusive to Live Science Pro
The super El Niño could cause torrential rainstorms. Americans may need to stock up on food to prepare, experts say.'Mpox has not disappeared': Why the infectious disease is still spreading in the US and may be here to stayInfectious diseases will seed new ground as the planet warms — here's where they'll spread
Due to this year's strong El Niño, Florida is expecting a rainier winter, which could mean even more mosquitoes than usual, Lucas noted. That, in turn, could fuel additional dengue cases.
This article is for informational purposes only and is not meant to offer medical advice.
Hence then, the article about why are dengue cases surging in florida this year an unlucky combination of factors experts say was published today ( ) and is available on Live Science ( Middle East ) The editorial team at PressBee has edited and verified it, and it may have been modified, fully republished, or quoted. You can read and follow the updates of this news or article from its original source.
Read More Details
Finally We wish PressBee provided you with enough information of ( Why are dengue cases surging in Florida this year? An 'unlucky' combination of factors, experts say )
Also on site :
- Witney Carson Claps Back at ‘DWTS’ Judge Carrie Ann Inaba, Joining Uproar Over Comments on Guillermo Rodriguez: ‘I Said What I Said’
- Tom DeLonge Was in the Crowd When 43,000 Fans Serenaded Him With His Own Song: ‘He Was Definitely in His Feels’
- James Gunn Responds to ‘Clayface’ Criticism: ‘The Public Voting on What IP They Want to See’ Isn’t ‘the Only Way to Make a Movie’