PlasmodiumandBabesia

Plasmodium and Babesia are intraerythrocytic apicomplexan parasites that cause malaria and babesiosis, respectively. Both organisms can cause severe, life-threatening disease. Malaria is transmitted through the bite of an Anopheles mosquito primarily in the tropics and subtropics while babesiosis is transmitted through the bite of an ixodid tick and is mostly found in temperate regions. The most common Plasmodium species to infect humans are Plasmodium falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi. Of these, P. falciparum is responsible for the greatest morbidity and mortality worldwide. Babesia microti and B. divergens are the most common causes of human babesiosis in the United States and Europe, respectively. Diagnosis of both is traditionally accomplished through microscopic examination of conventional Giemsa-stained thick and thin blood films. The thick film provides the greatest sensitivity for parasite detection and is preferred for screening, while the thin film provides the best morphology for differentiation of Babesia and Plasmodium parasites and Plasmodium species determination. Antigen detection methods are also widely used for detection of malaria and molecular amplification methods have been described for both organisms.