The Centers for Disease Control and Prevention issued a health alert Monday evening after they said five malaria cases were recently acquired in Florida and Texas.
Four cases were documented in Florida and one in Texas, and the CDC says this is the first time in 20 years to be acquired locally.
"Locally acquired mosquito-borne malaria has not occurred in the United States since 2003 when eight cases of locally acquired P. vivax malaria were identified in Palm Beach County, Florida," the health alert stated.
The CDC said there is no evidence that the cases between the two states are related.
Texas officials stated that the person diagnosed with malaria did not travel outside the country or state.
Malaria is a serious and potentially fatal disease transmitted through the bite of an infective mosquito. Symptoms include fever, chills and flu-like illnesses, health officials said.
The CDC said the temperature is "particularly critical" where the mosquitos carrying malaria can survive and multiply.
"Generally, in warmer regions … transmission will be more intense," the CDC stated.
Unprecedented heat continues to bake much of the South and Southeast. In Texas, residents have been dealing with the oppressive temperatures for weeks, and there’s no relief in sight as the heat continues to expand to more areas of the country.
The FOX Forecast Center is tracking long-range forecast models indicating the overall pattern leading to this extreme heat will linger into early July. What makes this especially dangerous is the number of consecutive days with heat indices close to or above 100 degrees.
According to the CDC, about 2,000 cases of malaria are diagnosed in the U.S. each year. The vast majority of cases in the United States are in travelers and immigrants returning from countries where malaria transmission occurs, many from sub-Saharan Africa and South Asia.
All of the patients have received treatment and are said to be improving.