Florida Confronts Record Dengue Fever Outbreak

Florida is currently contending with its most significant dengue fever outbreak to date, with hundreds of confirmed cases, including a notable rise in locally transmitted infections.

According to the Centers for Disease Control and Prevention (CDC), Florida has reported a total of 484 dengue fever cases. Of these, 243 were acquired locally, and 241 were acquired internationally. This marks a substantial increase compared to the previous year, when Florida recorded 72 local cases and 445 internationally acquired cases.

In response to the escalating spread, three counties—Hillsborough, Pasco, and Pinellas—declared states of emergency last week. Hillsborough County has reported at least 160 dengue fever cases, while Pinellas County has recorded seven and Pasco County has reported two. Miami-Dade County has also documented seven cases. Additionally, Orange County has reported three cases, and Palm Beach County has one.

Nationally, the contiguous United States has seen 541 travel-associated dengue cases across 40 states, alongside 244 locally acquired cases. These figures include the infections in Florida and one case in Virginia.

Dengue, often referred to as 'breakbone fever,' is characterized by symptoms that typically include a sudden high fever, severe headache, pain behind the eyes, and deep aches in muscles, joints, and bones. The virus is transmitted through the bite of infected Aedes mosquitoes, primarily the Aedes aegypti species, which is common in Florida.

The state's warm and humid climate creates an environment conducive to the proliferation of these mosquitoes. These insects can breed in even small amounts of standing water, such as in a bottle capful.

While dengue fever infections are often asymptomatic, they can lead to severe and life-threatening conditions in some individuals. These can include internal bleeding, respiratory distress, heart failure, shock, and organ failure, particularly affecting the liver, brain, and heart.

Health officials indicate that between 40 to 80 percent of dengue fever infections do not present symptoms. When symptoms do appear, they typically manifest abruptly about five to seven days after infection. Warning signs include a fever exceeding 100°F (38°C), severe headaches, pain behind the eyes, muscle or joint pain, and bleeding gums. Some patients may also experience facial redness within the first 24 to 48 hours of symptom onset. Severe cases can involve intense abdominal pain, persistent vomiting, lethargy, and dengue shock syndrome, a critical condition characterized by severe bleeding that causes a rapid drop in blood pressure.

Individuals under five years old, adults over 65, and pregnant women are considered at higher risk of severe complications from the virus.

Dengue was largely eradicated from the United States in the 1970s but has reappeared in sporadic outbreaks since, predominantly in warmer states like Florida and California. The majority of dengue cases recorded in the U.S. are linked to international travel.

There is no specific antiviral cure for dengue fever. Treatment focuses on supportive care to manage symptoms and complications. For mild cases, doctors recommend ample fluid intake and pain relief medication such as Tylenol. Severe cases may necessitate hospitalization for intravenous fluids, blood pressure monitoring, and blood transfusions to address blood loss.

A three-dose vaccine is available for dengue fever and is recommended for children aged nine to 16. This vaccine has been shown to reduce the risk of symptomatic infection by approximately 80 percent.

Earlier this year, a CDC report highlighted a significant rise in average annual dengue cases in the U.S., showing a 359 percent increase in 2024 compared to the 2010-2023 annual average. In 2024, a record 3,798 dengue fever cases were reported, a sharp increase from the average of 828 cases. Of these, 97 percent were travel-associated, while 105 cases, or three percent, were locally acquired. Among all reported cases, 36 percent required hospitalization, three percent were severe, and six deaths were recorded.