Doctors have been warning that Chikungunya fever, a tropical disease that causes severe joint pain, would soon reach the continental United States. Now it has done so, federal and state officials said Thursday.

The first domestically acquired cases were found in two Florida residents, one from the Miami area and one from Palm Beach, according to the state’s Health Department. Neither had traveled to countries where the mosquito-borne disease is endemic. One case has been confirmed by the Centers for Disease Control and Prevention; the second has not.

While seldom fatal, the Chikungunya virus (pronounced CHIK-en-goon-ya) causes high fever and sometimes a rash in addition to joint pain. Its name, from the Makonde language of East Africa, refers to people walking “bent up” with pain. In about 20 percent of patients, the pain can last a year or more.

The disease has been widespread in the tropics for centuries, but until 50 years ago it was confused with dengue fever, which kills far more people.