Health Officials Confirm Locally Acquired Dengue Fever Case in Miami-Dade Amid Peak Mosquito Season This Year

The Florida Department of Health in Miami-Dade County has confirmed a locally acquired case of dengue fever, issuing an advisory as officials begin coordinating surveillance, prevention and mosquito control efforts in South Florida.

According to the advisory, the confirmed case involved transmission of the virus within the local area, rather than a case in which someone contracted the disease while traveling abroad and later returned to Florida. Health officials have not disclosed the exact neighborhood or specific location where the local transmission likely occurred, though the department said it has begun coordinated surveillance, prevention and mosquito control efforts in the area in response to the confirmed case.

Dengue is a viral illness spread primarily through the bite of Aedes aegypti mosquitoes, though the related Aedes albopictus species can also transmit the virus and is present in Florida as well. The disease typically presents as a flu-like illness, with symptoms that can include fever, severe muscle aches, joint pain and, in some cases, a skin rash. Symptoms of dengue generally appear within 14 days of being bitten by an infected mosquito and typically last anywhere from four days to a week once they develop.

Dengue fever is not considered contagious between people under normal circumstances and is rarely fatal, though the illness can be severely uncomfortable, having earned the nickname “breakbone fever” in some medical literature because of the intensity of the muscle and joint pain it can cause. In more severe cases, the disease can also cause gastrointestinal symptoms such as vomiting and diarrhea, along with symptoms like eye pain and, in rare instances, bleeding complications.

Miami-Dade’s confirmed local case comes during what public health officials have identified as the most active period of the year for dengue transmission in Florida, driven by the combination of summer heat, humidity and standing water that creates favorable breeding conditions for Aedes mosquitoes. The Centers for Disease Control and Prevention has reported a significant national rise in dengue activity over the past year, with federal surveillance data showing a 359% increase in reported U.S. dengue activity compared with historical averages, even as the large majority of cases nationally continue to be linked to international travel rather than local transmission.

Florida has recorded locally acquired dengue cases every year in recent years, with the state reporting 62 locally acquired cases in 2025, spread across Brevard, Hillsborough, Miami-Dade and Pasco counties. Miami-Dade County alone accounted for 25 of those 2025 cases. In 2023, Florida recorded an even higher total of 154 locally acquired dengue cases, with Miami-Dade County responsible for 139 of them, reflecting the county’s position as one of the state’s most consistent hot spots for local dengue transmission given its dense population, tropical climate and extensive history of international travel connections. Separately, the Florida Department of Health in Hillsborough County reported the state’s first locally acquired dengue case of 2026 in that county earlier this summer.

Currently, no dengue vaccine is approved for use among the general adult population in the United States. The one FDA-approved vaccine, Dengvaxia, is authorized only for children ages 9 to 16 who have laboratory-confirmed evidence of a prior dengue infection and who live in dengue-endemic U.S. territories such as Puerto Rico, and its manufacturer has announced plans to discontinue production of the vaccine in 2026. For the vast majority of Florida residents and mainland U.S. travelers, preventing dengue infection depends entirely on avoiding mosquito bites in the first place, since no widely available vaccine or specific antiviral treatment currently exists for the general population.

Public health officials have outlined several practical steps residents can take to reduce their risk of exposure to dengue-carrying mosquitoes. Using insect repellent registered with the Environmental Protection Agency remains one of the most effective preventive measures, alongside wearing long sleeves and pants during outdoor activities, particularly during the daytime hours when Aedes mosquitoes, unlike many other mosquito species, are most actively biting. Eliminating any standing water around homes and properties is also considered essential, since Aedes mosquitoes require only small amounts of stagnant water, such as that collecting in flowerpots, discarded containers, clogged gutters or unused tires, to breed successfully.

Miami-Dade has faced elevated mosquito-borne illness activity beyond dengue in recent months as well. The county confirmed its first locally acquired case of chikungunya, another mosquito-borne viral illness, in December, and the broader South Florida region has continued monitoring for both diseases throughout 2026 given the area’s consistent risk profile for Aedes-transmitted infections. Chikungunya, like dengue, is transmitted primarily by Aedes mosquitoes and causes symptoms including high fever and often debilitating joint pain, typically appearing within three to seven days of a bite from an infected mosquito.

With Florida now entering the height of its summer mosquito season, health officials in Miami-Dade and across the state are expected to continue closely monitoring both human case counts and mosquito surveillance data throughout the coming months, using that information to guide targeted mosquito control efforts and public health messaging in areas where infected mosquito populations or additional human cases are identified.