US issues alert after first local malaria spread in 20 years

The US Centers for Disease Control and Prevention has issued an alert after reporting first locally acquired cases of malaria in 20 years. The CDC confirmed four cases of the mosquito-borne illness in Florida and one in Texas in its health alert, adding the cases in the two states did not seem to be related.

"All patients have received treatment and are improving. 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," CDC said.

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. Texas also issued a health advisory.


Despite the recent cases, the risk of locally acquired malaria remains extremely low in the United States, the CDC said.

But CDC warned that Anopheles mosquito vectors, found throughout many regions of the country, are capable of transmitting malaria if they feed on a malaria-infected person. The risk is higher in areas where local climatic conditions allow the Anopheles mosquito to survive during most of or the entire year and where travelers from malaria-endemic areas are found, CDC said.

CDC has advised clinicians to consider a malaria diagnosis in any person with a fever of unknown origin regardless of their travel history, in addition to routinely considering malaria as a cause of febrile illness among patients with a history of international travel to areas where malaria is transmitted.

"Prompt diagnosis and treatment of people with malaria can prevent progression to severe disease or death and limit ongoing transmission to local Anopheles mosquitos. Individuals can take steps to prevent mosquito bites and control mosquitos at home to prevent malaria and other mosquito-borne illnesses," CDC said.