Four local cases of malaria caused by Plasmodium vivax have been identified in Sarasota County, according to the Florida Department of Health. The individuals affected have received treatment and recovered. The Centers for Disease Control and Prevention (CDC) has noted that increased international travel during the summer could raise the risk of malaria being introduced into local mosquito populations. Travelers infected with malaria who are bitten by mosquitoes can lead to new local cases, even among people without a history of travel.
Malaria is a potentially serious disease resulting from infection with one of four species of Plasmodium parasites. While infections with Plasmodium vivax tend to be less severe, they can result in chronic illness due to dormant parasites remaining in the liver. The Florida Department of Health emphasized that suspected or confirmed cases should be evaluated and managed quickly.
The primary method of transmission is through bites from infected Anopheles mosquitoes. Other rare forms of transmission include mother-to-child during pregnancy or childbirth, as well as exposure to contaminated blood, tissues, or needles. To prevent further spread, those diagnosed with malaria are advised to avoid mosquito bites while ill.
Regions where malaria is endemic include Africa, South and Southeast Asia, the Middle East, Central America (including Mexico), and South America. The incubation period for malaria typically ranges from 7 to 30 days depending on the species involved.
Symptoms often resemble flu-like illnesses and may include cyclical fever, nausea, vomiting, diarrhea, headache, and muscle pain. Laboratory findings may show anemia, low platelet counts (thrombocytopenia), elevated bilirubin levels, and increased aminotransferases. Severe symptoms can involve seizures, confusion, hemoglobinuria, kidney failure, acute respiratory distress syndrome, coma, and high levels of parasitemia (over 5%). Pregnant women and young children face a higher risk for severe disease.
Treatment decisions depend on several factors such as the specific parasite species involved, patient health status, drug resistance patterns in regions where exposure occurred, and prior use of antimalarial medications. Information about treatment options is available at www.cdc.gov/malaria/diagnosis_treatment/clinicians1.html. For severe cases requiring intravenous artesunate—a commercially available medication—hospital pharmacists can call 1-855-526-4827 for distribution information. Eradication of dormant forms from P. vivax or P. ovale requires primaquine phosphate or tafenoquine; however, patients should undergo G6PD testing before receiving these drugs due to risks associated with G6PD deficiency.
Prevention strategies focus on avoiding mosquito bites and using chemoprophylaxis when appropriate after assessing individual travel risk.
For diagnosis, smear microscopy remains the gold standard; results should be provided within hours. If unavailable immediately, clinicians are advised to use the BinaxNOW rapid diagnostic test but confirm all results with microscopy afterward. Polymerase chain reaction tests may help confirm species after initial diagnosis by microscopy. Additional laboratory findings might include mild anemia or thrombocytopenia as well as elevated bilirubin or aminotransferases.
Clinicians seeking guidance on sample submission can contact their county health department for assistance with protocols involving the Florida Department of Health’s Bureau of Public Health Laboratories.
Additional resources are available through county health departments and online via the CDC’s malaria page at www.cdc.gov/malaria/index.html and Malaria 101 training for healthcare providers at www.cdc.gov/parasites/cme/malaria/index.html. The CDC also operates a Malaria Hotline at (770) 488-7788 during business hours or (770) 488-7100 after hours.
The Florida Department of Health is accredited by the Public Health Accreditation Board and works statewide to protect public health through coordinated efforts across state and community levels.
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