infectious diseases
Malaria
Introduction
Malaria is infection withPlasmodiumspecies. Symptoms and signs include fever (which may be periodic), chills, rigors, sweating, diarrhea, abdominal pain, respiratory distress, confusion, seizures, hemolytic anemia, splenomegaly, and renal abnormalities. Diagnosis is by seeingPlasmodiumin a peripheral blood smear and by rapid diagnostic tests. Treatment and prophylaxis depend on thePlasmodiumspecies and drug sensitivity and the patient's clinical status. Treatment regimens for acute disease include artemisinin-based combination therapy, the most rapidly acting regimen, the fixed combination ofatovaquoneand proguanil, and, less commonly,chloroquine,quinine, ormefloquine. Patients infected withP. vivaxandP. ovalealso receiveprimaquineor a single dose oftafenoquineto prevent relapse. Prophylaxis is usually with the fixed combination ofatovaquoneplus proguanil or withdoxycycline;chloroquineis used in areas withoutchloroquineresistance. Terminal treatment withprimaquineortafenoquineis given to patients likely to have been exposed toP. vivaxorP. ovale. Malaria is infection withPlasmodiumspecies. About half of the world’s population is at risk of malaria. Malaria is endemic in Africa, India and other areas of South Asia, Southeast Asia, North and South Korea, Mexico, Central America, Haiti, the Dominican Republic, South America (including northern parts of Argentina), the Middle East (including Turkey, Syria, Iran, and Iraq), and Central Asia. The Centers for Disease Control and Prevention (CDC) provides information about specific countries where malaria is transmitted (seeCDC: Yellow Fever and Malaria Information, by Country), types of malaria, resistance patterns, and recommended prophylaxis (seeCDC: Malaria). In 2020, there were an estimated 241 million cases of malaria, with 95% of them in Africa (see2021 World Malaria Report). An estimated 627,000 people died from malaria in 2020, mostly children < 5 years of age. Since 2000, deaths due to malaria have decreased by approximately 30% through the efforts of theRBM (Roll Back Malaria) Partnership to End Malaria, which has > 500 partners (including endemic countries and various organizations and institutions). Despite decades of decline, the number of deaths increased in 2020 as a result of disruptions due to the COVID-19 pandemic. Malaria once was endemic in the US. Currently, about 1500 cases occur in the US each year. Nearly all are acquired abroad, but a small number result from blood transfusions or rarely from transmission by local mosquitoes that feed on infected immigrants or returning travelers. 