Should Florida Follow Costa Rica's Malaria Elimination Strategy

Malaria is one of the world's most significant public health problems, and it could become a concern in the State of Florida.

The U.S. Centers for Disease Control and Prevention (CDC) confirmed a sporadic, locally-acquired malaria case in Sarasota and Manatee Counties on June 2, 2023. This person is currently recovering from this malaria infection. 

Florida's Department of Health (DOH) stated it is working closely with local partners to prevent further malaria transmission. It has conducted aerial and truck spraying where the recent malaria case lives. 

The CDC says locally acquired mosquito-transmitted malaria cases can occur, as Anopheles mosquito vectors exist throughout the U.S. The largest recent outbreak of local malaria cases occurred in Palm Beach County in 2003, with eight cases.

Typically, about 2,000 malaria cases are diagnosed each year in the U.S.

In addition to routinely considering malaria for febrile patients with a history of travel to areas where malaria is transmitted, malaria diagnosis should also be considered in any person with a fever of unknown origin, regardless of travel history.

Especially pregnant women.

The CDC says malaria infection during pregnancy can lead to miscarriage, premature delivery, low birth weight, congenital infection, and/or perinatal death.

Once a diagnosis of malaria has been made, appropriate antimalarial treatment must be initiated immediately, says the CDC. The Malaria Treatment Tables can be used as a guide in the U.S.

Overall, the CDC says the risk of a malaria outbreak in Florida is low.

A real-world example of how to manage a malaria outbreak in Costa Rica.

The Costa Rican Ministry of Health recently reported an outbreak of P. falciparum malaria in Limón Province, primarily affecting the cantons of Pococí and Limón. 

As of June 8, 2023, the Huetar Norte Region reported 131 malaria cases.

The Ministry of Health began the second administration of antimalarial treatment in the canton of Los Chiles in early June 2023 in the towns of Medio Queso, Coquital, and San Gerardo.

The administration of this medication consisted of two to three complete cycles per person, with a distance of four weeks between each dose, administered orally. This strategy has been implemented for the last four years in Costa Rica.

"The administration of this treatment aims to eliminate the transmission of the parasite," indicated Dr. Mary Munive, Vice President of the Republic and Minister of Health, in a press release on June 6, 2023.

This initiative was given thanks to the donation by the Ministry of Health of Mexico and the Pan American Health Organization, which provided the country with 75,000 chloroquine tablets.

The CDC issued a Level 2, Practice Enhanced Precautions advisory on April 17, 2023, to alert visitors to Costa Rica.

CDC recommends travelers to any area of Costa Rica use mosquito avoidance measures to protect from malaria and other diseases spread by mosquito bites.

Previously, the CDC only recommended malaria chemoprophylaxis for travelers to Alajuela Province near the border with Nicaragua.

However, the CDC currently recommends malaria chemoprophylaxis for travelers visiting Limón and Alajuela Provinces in Costa Rica. 

From a preventive vaccine perspective, malaria vaccines are currently being deployed in Africa and are unavailable in the U.S. as of June 14, 2023.