FLORIDA — Hillsborough County officials declared a local state of emergency on 24 September in response to dengue fever infections. Pasco County and Pinellas County have also declared local states of emergency in relation to dengue reports.

The Florida Department of Health reported one death related to dengue. Hillsborough County officials said the spread of dengue poses "an immediate and widespread threat to the public health, safety, and welfare of the residents and visitors of Hillsborough county."

Declaring a local state of emergency enables Hillsborough County to request state, federal, and local emergency funds, grants, financial assistance, and mutual aid. The initial emergency declaration in Hillsborough County was put into effect for one week. Hillsborough County declared a state of emergency for seven days initially, but the declaration can be extended in seven-day increments if necessary, as outlined in Hillsborough County Code of Ordinances, Section 22-22.

Hillsborough County Mosquito Control has historically managed mosquito populations through source reduction, larviciding, and adulticiding, but the dengue outbreak required unprecedented measures such as aerial treatments and inter-county collaboration. Hillsborough County authorities reported zero mosquito test pools testing positive recently. Hillsborough County officials stated that controlling dengue requires immediate, aggressive, and continuous measures such as pesticide application, public education, and emergency resource planning.

"This is wildly unusual for us," Chris Wilkerson, a spokesperson for Hillsborough County, told reporters. The Florida Department of Health has a history of issuing mosquito-borne illness advisories in response to outbreaks, including one issued on July 28, 2026, for Hillsborough County. The Florida Department of Health has authority under Chapter 252, Florida Statutes, to issue mosquito-borne illness advisories and coordinate public health responses during outbreaks.

There were 26 cases of international travel-linked dengue reported in Florida during a six-day period beginning on 13 September. There were 38 locally contracted dengue cases reported in Florida over the same six-day period beginning on 13 September. Dengue is contracted through the bite of mosquito species, largely Aedes aegypti and Aedes albopictus. Both Aedes aegypti and Aedes albopictus mosquito species are present in Florida.

Symptoms of dengue show up between three days and two weeks after a bite from an infected mosquito. Symptoms of dengue typically span four days to one week. The Florida state health department said symptoms include "sudden onset of fever, severe headache, eye pain, muscle and joint pain … and bleeding. Gastrointestinal symptoms like vomiting and diarrhea may also be present in some cases." Dengue hemorrhagic fever is a rarer form of the illness that can be fatal without proper supportive care.

The 190 locally acquired cases in Florida are the second-highest in state history, with 199 reported in 2023. In 2023, the last major outbreak of locally acquired dengue in Florida occurred in Key West. Florida reported 62 locally acquired dengue cases last year. The last major outbreak of dengue cases acquired outside of the Texas-Mexico border since 1945 was in 2009 in Key West, Florida.

"I do think it’s going to be somewhat the new normal," Michael von Fricken, a University of Florida associate professor of environmental and global health, told reporters.

Why It Matters

The declaration of local states of emergency in Hillsborough, Pasco, and Pinellas counties signals a coordinated regional response to a surge in locally acquired dengue cases that ranks among the highest in state history. The involvement of multiple counties and the activation of emergency powers allow for the deployment of resources such as aerial treatments and mutual aid, which are not part of standard mosquito control operations. This shift from historical management practices to emergency measures reflects the scale of the current outbreak and the immediate threat identified by county officials.The presence of 190 locally acquired cases places the outbreak near the record high set in 2023, indicating a sustained pattern of local transmission rather than isolated incidents. With both Aedes aegypti and Aedes albopictus mosquitoes present in Florida, the potential for continued spread remains a public health concern. The Florida Department of Health's authority to issue advisories and coordinate responses under state statutes provides the legal framework for these actions, while the US Centers for Disease Control and Prevention reported 3 locally acquired dengue cases in the continental United States outside of Florida.

What's New

Hillsborough County Mosquito Control has historically managed mosquito populations through source reduction, larviciding, and adulticiding, but the 2026 dengue outbreak required unprecedented measures such as aerial treatments and inter-county collaboration. In 2023, the last major outbreak of locally acquired dengue in Florida occurred in Key West, marking a significant gap in local transmission before the 2026 surge.

How Sources Differ

Regarding locally acquired cases, the Florida Department of Health report on mosquito-transmitted viruses stated that the Florida Department of Health reported 190 locally acquired cases of dengue across the state, while Florida Department of Health historical data indicated that Florida reported 62 locally acquired dengue cases last year. On the topic of dengue cases, Florida Department of Health historical data noted that Florida reported 62 locally acquired dengue cases last year, whereas the Florida Department of Health report on mosquito-transmitted viruses reported that there were 38 locally contracted dengue cases reported in Florida over the same six-day period beginning on 13 September.

Concerning locally acquired cases, the Florida Department of Health report on mosquito-transmitted viruses stated that there were 38 locally contracted dengue cases reported in Florida over the same six-day period beginning on 13 September, while Florida Department of Health historical data asserted that the 190 locally acquired cases in Florida are the second-highest in state history, with 199 reported in 2023. Regarding dengue outbreaks, nypost.com reported that the last major outbreak of dengue cases acquired outside of the Texas-Mexico border since 1945 was in 2009 in Key West, Florida, while the Florida Department of Health report on mosquito-transmitted viruses stated that the Florida Department of Health reported 190 locally acquired cases of dengue across the state.

On the subject of the Florida Department of Health, the Florida Department of Health report on mosquito-transmitted viruses noted that the Florida Department of Health reported 190 locally acquired cases of dengue across the state, while primary source + the Florida state health department said symptoms include "sudden onset of fever, severe headache, eye pain, muscle and joint pain … and bleeding. Gastrointestinal symptoms like vomiting and diarrhea may also be present in some cases". Regarding the Florida Department of Health, the Florida Department of Health report on mosquito-transmitted viruses stated that the Florida Department of Health reported 190 locally acquired cases of dengue across the state, while the Florida Department of Health report indicated that the Florida Department of Health reported one death related to dengue.