Four things to know about malaria cases in the United States

For the first time in 20 years, five people have picked up malaria on U.S. soil.

On June 26, the U.S. Centers for Disease Control and Prevention issued a health advisory, announcing that over the last two months four people in Sarasota County, Fla, and one person in Cameron County, Texas, had developed the mosquito-borne illness. The new cases mark the first time since 2003 that U.S. residents have contracted malaria after being bitten by a mosquito close to home. All five people received treatment and are improving.