Florida Logs 252 Locally Acquired Dengue Cases in 2024, Surpassing Hawaii 2015-2016 Record in Continental US

State surveillance data show 252 autochthonous infections versus 245 travel-associated cases, reversing the usual pattern. Hillsborough County accounts for the majority, prompting emergency declarations and intensified Aedes aegypti control. One death occurred in an elderly Tampa resident on September 4. CDC records indicate prior continental peaks remained below 200 cases per year since Key West re-emergence in 2009-2010.

Warmer temperatures have expanded Aedes aegypti range northward, yet Tampa’s surge exceeds Miami’s typical burden. Serotype diversity and absence of prior immunity in local populations amplify secondary infection risk through antibody-dependent enhancement, a mechanism documented in NEJM reviews of dengue pathogenesis. WHO global totals exceed 2.2 million cases, underscoring importation pressure from endemic regions.

Local transmission now outpaces imported infections, indicating sustained vector-human cycles rather than repeated seeding. This shift challenges standard travel-screening models and highlights gaps in real-time serotype surveillance. Next steps require prospective cohort studies tracking secondary infections and vector competence under projected climate scenarios.

Evidence remains observational from passive surveillance systems; active case-finding and seroprevalence surveys are needed to quantify true incidence and transmission intensity.