Four people in Sarasota have fallen ill with malaria, and the Florida Department of Health has issued a statewide mosquito-borne illness alert, the department said this week. The four people in Sarasota who were ill after being bitten by infectious mosquitoes have all recovered. According to state health officials, it is less fatal than other species. Malaria symptoms include headaches, nausea, vomiting, sweating, fever and chills. The U.S. has not seen locally transmitted malaria cases since an outbreak in Palm Beach County in 2003, when there were eight cases.