Florida Records Dengue Death as Hillsborough Faces Unusual Outbreak

Florida has confirmed a death from dengue fever, as the state contends with one of its most severe outbreaks of the mosquito-borne illness in decades.

The Florida Department of Health announced the death on Friday but released no further details. The fatality is linked to an outbreak in Hillsborough County, where more than 130 locally acquired dengue cases have been reported this year — a striking figure for an area that normally records only a handful.

"This is wildly unusual for us," said Chris Wilkerson, a spokesperson for the county.

The death was first reported by the Tampa Bay Times, which identified the victim as an elderly woman from Tampa who died on September 4.

Dengue is caused by a virus transmitted by a warm-weather mosquito species whose range is expanding due to climate change, experts say. The current Florida outbreak is likely tied to recent weather conditions that enabled the virus-carrying mosquitoes to multiply.

For decades, most dengue cases reported in the United States involved travelers infected abroad, along with locally acquired infections in Puerto Rico. In 2009-2010, Key West, Florida, recorded the first dengue cases acquired within the continental U.S. outside the Texas-Mexico border area since 1945.

The state's highest annual count — nearly 200 cases — occurred in 2023. This year's total already ranks second, with 152 locally acquired cases reported so far, according to the Florida Department of Health.

Because many infected people do not fall ill, the number of reported cases in an outbreak can undercount the true scale of infections. Some patients experience headache, fever and flu-like symptoms, while severe cases can lead to serious bleeding, shock and death.

Globally, more than 2.2 million infections have been reported this year, with nearly 1,200 deaths, according to the World Health Organization. In the United States, nearly 1,500 locally acquired cases have been recorded, most of them in Puerto Rico, according to the Centers for Disease Control and Prevention.

The current outbreak is concentrated just north of Tampa, where crews have been spraying to kill mosquitoes around the clock. Workers are also inspecting properties for standing water, including in tires where mosquitoes may breed, said Paolo Pecora, senior environmental scientist for Hillsborough County Mosquito Management Services.

Recent mosquito sampling has not detected the virus, suggesting the likelihood of new infections is declining, Pecora said.

Outbreaks can begin when a traveler becomes infected abroad and is then bitten in the U.S. by a mosquito capable of spreading the virus, after which the disease can spread rapidly, said Michael von Fricken, a University of Florida associate professor of environmental and global health.

Given the recurring abundance of such mosquitoes in Florida, the dengue threat is unlikely to fade, he added. "I do think it's going to be somewhat the new normal," he said.