Several Florida counties have declared states of local emergency as dengue fever infections rise.
Hillsborough county officials issued their declaration on 24 September after health authorities confirmed 134 dengue cases. The mosquito-borne disease is more commonly associated with countries outside the US. Officials warned that its spread represented “an immediate and widespread threat to the public health, safety, and welfare of the residents and visitors of Hillsborough county”.
Containing the tropical illness – sometimes called breakbone fever because of the intense pain it can cause – will require “immediate, aggressive, and continuous” action, officials said. Measures include pesticide spraying, public education and emergency resource planning.
Dengue infections have been reported with increasing frequency in parts of the US. In 2023, Long Beach and Pasadena recorded California’s first known locally acquired cases.
The range of dengue-carrying mosquitoes has extended beyond tropical and subtropical regions, reaching England as well. Authorities recently said Aedes aegypti mosquitoes had been discovered inside homes in east London.
Scientists have warned that global warming is likely to worsen diseases linked to climate conditions.
The emergency declaration allows Hillsborough county, whose seat is Tampa, to seek “any available and necessary state, federal, and local emergency funds, grants, financial assistance, and mutual aid” for efforts to control dengue-carrying mosquitoes. The initial order lasts one week, although officials have the authority to extend it.
Nearby Pasco and Pinellas counties have issued similar emergency declarations following dengue reports.
In its latest report on mosquito-borne viruses, the Florida department of health said 26 cases of travel-associated dengue were reported during the six-day period beginning 13 September. The state has recorded 212 travel-related cases so far in 2026.
During that same period, Florida reported 38 locally acquired dengue infections. They formed part of the 190 locally contracted cases recorded across the state, according to the health department.
Figures from the US Centers for Disease Control and Prevention (CDC) were slightly different. As of Monday, the agency said Florida had reported 392 dengue cases in total so far this year, alongside varying data for individual counties.
Dengue is transmitted by bites from infected mosquitoes, primarily Aedes aegypti and Aedes albopictus. Both species are found in Florida.
Symptoms can develop three days to two weeks after a person is bitten by an infected mosquito. They include “sudden onset of fever, severe headache, eye pain, muscle and joint pain … and bleeding”. Some people may also experience gastrointestinal symptoms, including vomiting and diarrhea, the Florida health department said.
Symptoms generally last between four days and one week. A less common form, dengue hemorrhagic fever, can be fatal without appropriate supportive treatment, the state health department said.
Hillsborough county officials remain hopeful that infections will decline in the coming weeks. The local outlet Bay News 9 reported that no recent “mosquito test pools” had tested positive.
