Dengue Outbreak in Florida Reaches Unprecedented Levels Since the 1930s

Florida is grappling with a dengue outbreak of a scale unseen since the 1930s, with hundreds of locally-acquired infections spreading across multiple counties.

A report by FOX 35 Orlando highlights that experts are deeming the current situation as Florida's most significant dengue outbreak since the 1930s, when the state faced a major epidemic.

The Florida Department of Health's arbovirus surveillance report for the week of September 27 to October 3, 2026, notes 296 locally-acquired dengue cases so far this year.

During that week alone, 44 new local infections were reported. Health authorities have also identified 262 cases linked to international travel, bringing the total dengue infections in Florida in 2026 to 558. It's important to differentiate these categories as not all cases were contracted within the state.

Hillsborough County at the Center of the Outbreak

The outbreak's epicenter is Hillsborough County, with 259 of the 296 local cases. Following are Pinellas with 20 cases, Miami-Dade with eight, Orange and Pasco with three each, and Broward, Palm Beach, and Polk with one case each.

This situation harks back to a scenario not seen in nearly 90 years. Historical public health documents indicate the last significant dengue epidemic in Florida occurred in 1934 and 1935, affecting areas like Miami and Tampa.

Expert Insights on the Outbreak

Beth McGraw, a biology professor at Pennsylvania State University, told FOX that Florida is experiencing "the largest outbreak since the 1930s."

McGraw linked the surge in cases to an extended, humid summer that facilitated mosquito breeding, alongside changes in mosquito distribution and increased resistance to some conventional insecticides.

"Previously, they were confined to tropical areas, but due to climate change, we're seeing them more frequently in the southern United States," McGraw explained.

Local Transmission Raises Concerns

A particularly worrying aspect is that many cases are not from travelers returning from dengue-endemic countries but from individuals bitten by infected mosquitoes within Florida.

The state health department confirmed that the 296 local cases reported by October 3 are spread across eight counties. In Hillsborough, 19 clusters of dengue-positive Aedes aegypti mosquitoes have been identified.

The outbreak has extended to South Florida. The Broward County Health Department recently confirmed its first locally-acquired dengue case in 2026, issuing a mosquito-borne illness advisory.

In early August, Miami-Dade had already confirmed local dengue transmission, prompting health and mosquito control authorities to enhance monitoring and preventative actions.

Impact and Prevention Measures

The outbreak has resulted in at least one death in Florida in 2026. In September, officials confirmed the year's first dengue-related death, an 80-year-old woman from Tampa who died on September 4.

Transmission spiked notably during August and September. The latest state report records 21 local cases with symptom onset in July, 154 in August, and 121 in September.

Dengue is a viral disease primarily spread through the bite of the Aedes aegypti mosquito. It is not transmitted directly from person to person under normal circumstances; rather, a mosquito can become infected by biting an infected person and then pass the virus to others.

Common symptoms include fever, headache, severe muscle and joint pain, pain behind the eyes, nausea, vomiting, and skin rashes. Although many experience mild symptoms, dengue can progress to severe forms that may cause bleeding, shock, and even death.

The Florida Department of Health advises eliminating containers and stagnant water around homes and businesses, as these can become mosquito breeding sites. It also recommends using repellents, wearing appropriate clothing to cover skin, and securing doors and windows.

Local authorities have ramped up fumigations and other control strategies. For instance, in Pinellas, Clearwater released 10,000 small fish that eat mosquito larvae in various lakes as part of efforts to reduce the insect population.

The Centers for Disease Control and Prevention (CDC) remind that, historically, most dengue cases in the contiguous United States have been linked to international travel. However, the widespread presence of mosquitoes capable of transmitting dengue makes local outbreaks possible.