A patient with fever and no recent travel could still have dengue. Florida’s local transmission highlights why clinicians and infection preventionists should look beyond travel history and recognize warning signs.
Florida’s dengue landscape is undergoing a significant transformation, shifting from sporadic travel‑associated introductions to a pattern of predictable seasonal transmission. This change reflects broader global trends, as dengue incidence reaches historic highs and climate‑driven ecological shifts expand the reach of Aedes‑borne viruses.
Florida’s subtropical climate, dense urban development, and high volume of international travel create ideal conditions for dengue to persist. Stable populations of Aedes aegypti provide a reliable ecological foundation for transmission, while rising temperatures, prolonged rainy seasons, and increasingly frequent extreme weather events accelerate mosquito breeding cycles. After-storm flooding, especially in neighborhoods with poor drainage or swales that retain water, creates persistent pockets of standing water that support rapid mosquito proliferation. Many Floridians unknowingly contribute to vector growth through everyday items that collect water, such as inflatable pools, toys, plant saucers, bird baths, and backyard pools that are not properly maintained.
Florida’s role as a major travel hub for the Caribbean and Latin America ensures the continual introduction of dengue serotypes capable of establishing local transmission chains. Early in the summer in Florida, most positive cases originate from travel to regions such as Puerto Rico and Cuba. As the season progressed, however, the pattern shifted: travel‑associated cases seeded local transmission, and locally acquired dengue became increasingly prevalent.
Dengue hemorrhagic fever, or DHF, represents the severe end of the dengue spectrum and is a critical concern for emergency departments and infection prevention teams. DHF typically occurs when a person becomes infected with a different dengue serotype than one they have previously encountered, triggering an exaggerated immune response. It is characterized by plasma leakage, severe thrombocytopenia, hemorrhagic manifestations such as mucosal bleeding, and the potential for rapid clinical deterioration, often around days 3 to 7 of illness.
For emergency departments, early recognition of dengue is vital. The illness often mimics influenza, COVID‑19, or other viral syndromes, with symptoms including fever, severe headache, retro‑orbital pain, myalgias, arthralgias, rash, and nausea. Many patients report daytime outdoor activities such as gardening or walking near bodies of water, classic exposure scenarios for Aedes aegypti, a diurnal feeder.
Community prevention remains a cornerstone of dengue control. Floridians should use EPA‑registered repellents such as DEET, Picaridin, or IR3535; eliminate standing water around homes and workplaces; maintain window and door screens; and adopt daytime bite precautions. Patients who test positive frequently report outdoor activities during peak mosquito hours, reinforcing the need for consistent protective measures. When spending time outside, Floridians should apply repellent and wear protective clothing, especially when gardening or walking near water where mosquitoes are likely to be present.
Looking ahead, dengue is poised to become a predictable summer‑season pathogen in Florida. Climate patterns continue to shift toward warmer temperatures and longer rainy seasons, creating environments where mosquito vectors thrive. For clinicians and infection preventionists, maintaining high suspicion for dengue during summer months, encouraging community prevention behaviors, supporting rapid testing and reporting, and educating staff on the distinction between uncomplicated dengue and warning signs of DHF will be essential.
