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 (10,000 confirmed cases) in Puerto Rico in 2007. In these locations, the high transmission season is from August to November and the low transmission season is from March until July.
Three outbreaks of dengue transmitted by mosquitoes have been reported by the CDC in the US (states). One was in Hawaii in 2001 and the second was in Texas in 2005 on the Mexican border. The third was in Key West, Florida in 2009. Secondary transmission is rare.
Recent data for year 2022 (as of October 5, 2022) show that 616 cases of dengue have been reported in the US states, and another 209 cases reported in the US territories.
