The Florida Department of Health on Monday issued a statewide “mosquito-borne illness” advisory after four cases of malaria were confirmed in Sarasota County.
A fifth case was confirmed in Texas, according to a health alert issued by the U.S. Centers for Disease Control and Prevention.
Federal health officials are warning doctors, especially those in Southern states where the weather is more friendly to the tropical mosquitoes that spreads malaria, to be aware of the possibility of infection. They also should think about how to access the IV drug that is the first-line treatment for severe malaria, the CDC said.
According to the Florida agency, the four people in Sarasota County received treatment and recovered. The CDC said the Texas patient was treated and “improving.”
Malaria is caused by a parasite that spreads through mosquito bites. Infected people can suffer fever, chills and flu-like illness. If untreated, infected people can develop severe complications and die.
According to the Florida advisory, “residents throughout the state should take precautions by applying bug spray, avoiding areas with high mosquito populations, and wearing long pants and shirts when possible — especially during sunrise and sunset when mosquitoes are most active.”
The health department said it is working with local partners and county mosquito control agencies. Aerial and ground mosquito spraying continues to be conducted “to mitigate the risk of further transmission.”
Monday's Florida advisory did not say when most recent two cases were confirmed. However, local health officials previously said a case was confirmed in the Sarasota-Manatee county area June 21 and another May 26. Officials didn’t specify where in region the transmissions were reported.
The first two discoveries triggered a mosquito-borne illness alert only for those counties. Both were a type of malaria known as P. vivax, which is not as fatal as others, officials said.
While the Florida and Texas cases are believed to be locally acquired, the CDC expressed concern the developments pose a concern for a potential rise in imported malaria transmission due to increased international summer travel.
Only bites from infected Anopheles mosquitoes can transmit the parasite that causes the disease to humans. Malaria is not transmitted person to person.
The disease can be treated at hospitals and other health care providers.
About 2,000 U.S. cases of malaria are diagnosed each year — the vast majority in travelers coming from countries where malaria commonly spreads.
The last time mosquito-borne malaria occurred in the U.S. was in 2008, when eight cases were identified in Palm Beach County.
The largest malaria death toll in recent years has been seen in children in sub-Saharan Africa.
Information from the Associated Press, NPR and Health News Florida's Rick Mayer was used in this report.