For the first time in 20 years, United States has recorded the first spread of mosquito-transmitted malaria, disease reported to have been locally acquired.
Out of the five cases recorded, Florida accounts for four patients while one was reported in Texas and they are now on treatment, BBC report says.
According to the Centres for Disease Control, surveillance for more cases is continuing, the report added.
The CDC further says that the risk of catching malaria in the US remains extremely low, adding that it was working with the Florida and Texas health departments and that those recently diagnosed and treated “are improving”.
Malaria is caused by being bitten by an infected mosquito. People cannot catch it from each other. But the insects catch it from infected people, thereby continuing a cycle.
Malaria is common in Africa, Asia and Central and South America but not the US.
However, Anopheles mosquitoes, found throughout many parts of the US, can transmit malaria, if they have fed on an infected person.
The risk is higher in areas where the climate means insects survive during most of the year travellers from malaria-endemic areas are found.
Infected people can suffer fever, sweats and chills. Malaria is an emergency and must be treated quickly with drugs to kill the parasite that causes the infection.
Using insect repellent and insecticide treated net can help protect against mosquito bites.
US doctors are being advised to consider malaria in any person with an unexplained fever, regardless of international travel history, particularly if they have visited or live in the affected areas of Florida or Texas.
Florida has issued a mosquito-borne illness alert after cases were discovered in Sarasota County and Manatee County, warning residents to drain standing water where mosquitoes can breed and wear long-sleeved shirts and pants, the BBC report says.