Twenty years after the U.S. noted eight locally acquired malaria cases, Florida has confirmed four malaria infections and Texas has seen one in the last two months, the CDC said June 26.
The CDC is working with the two state governments to investigate the locally acquired mosquito-transmitted Plasmodium vivax malaria cases, and the agency said the cases in the two states are not related.
The last time the U.S. reported local malaria cases was 2003, when eight infections were found in Palm Beach County, Fla. For the four recent cases in Sarasota County, Fla., all individuals have been treated and have recovered, the state's health department said June 26.
In Texas, a malaria case was detected in a person who works outdoors in Cameron County, the Texas Department of State Health Services said June 23, and the patient has received treatment and is improving, according to the CDC. Texas has not reported a locally acquired malaria case since 1994.
For one of the Florida cases, the CDC said June 2 it was collaborating with the state's health department and "conducted both aerial and truck spraying in the general area where the individual lives" for the "sporadic local case of malaria."
The risk of locally acquired malaria remains extremely low, according to the CDC. The agency recommends clinicians "consider the diagnosis of malaria in any person with a fever of unknown origin, regardless of international travel history, particularly if they have been to the areas with recent locally acquired malaria."
Hospitals are advised to stock malaria diagnostic tests, intravenous artesunate, artemether-lumefantrine and atovaquone-proguanil.
If malaria is left untreated, the illness can "progress to severe disease, a life-threatening stage, where mental status changes, seizures, renal failure, acute respiratory distress syndrome and coma may occur," the CDC said.