Molecular testing for Plasmodium is used for laboratory diagnosis and confirmation of malaria.
Malaria is a tropical disease that infects about 500 million people and causes 1.5-3.0 million deaths annually. About 90% of deaths occur in sub-Saharan Africa, and most occur in children younger than 5 years.
Malaria is mainly caused by four species of Plasmodium protozoan: Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale. A fifth species, Plasmodium knowlesi, has recently been identified and is found in some parts of Southeast Asia.
Optical microscopy of peripheral blood stained with Giemsa is the standard laboratory method for diagnosing and differentiating malaria parasites. Under optimal conditions, the sensitivity of the thick blood smear is estimated to be 10 to 30 parasites per microliter of blood. However, microscopic diagnosis requires considerable experience and may not be sufficiently sensitive and specific when the laboratory experience is inadequate, or the equipment is not very sophisticated. In addition, prolonged exposure to anticoagulant EDTA, transport conditions, and prior use of antimalarial drugs may alter the morphology of the parasites. It may adversely affect optical microscopy's ability to identify and differentiate Plasmodium species.
Molecular PCR testing is an excellent alternative method of diagnosing malaria. It has very high specificity and sensitivity compared to standard laboratory methods.
See also:
Malaria (Plasmodium sp.), Antibodies Total
