Florida health officials say a tourist contracted dengue fever while visiting Key West.
A statement Wednesday from the Florida Department of Health in Monroe County says the person, who is not a Florida resident, is recovering. It adds "all indications are that this infection was locally acquired," and mosquito control officials have intensified their activities in the southernmost city in the continental U.S.
Dengue fever is rarely fatal but causes debilitating pain. The virus is transmitted by the same mosquitoes that can carry Zika and chikungunya.
No Zika cases have been reported in the Keys, and the islands had been free of dengue since an outbreak ended in October 2010.
Florida reported one local dengue infection last year. Health officials have tracked 160 travel-related Zika cases statewide, including 37 involving pregnant women.