Most cases of dengue in the US are imported from people who traveled to or emigrated from endemic areas of the world. It is the most common cause of fever in travelers returning from tropical or subtropical areas of the Caribbean, Latin America, and Asia.
Dengue infections are seen in US citizens who live in the territories of Puerto Rico, the US Virgin Islands, Samoa, and Guam, where the Aedes aegypti mosquito is found in large numbers year-round. There was a large epidemic in 2024 continuing into 2025, which affected Puerto Rico and the US Virgin Islands. In these locations, the high transmission season is from August to November, and the low transmission season is from March until July.
Local transmission of dengue has been reported in California, Florida, and Texas in 2024. Recent data for the year 2024 show that >6,000 cases of locally acquired dengue have been reported in the US states.
