Prevalence of Plasmodium falciparum and P. vivax in an area of transmission located in Pará State, Brazil, determined by amplification of mtDNA using a real-time PCR assay.

The need for a more sensitive and time-efficient assay for malaria has led to the development of molecular assays involving real-time PCR (qPCR), a procedure that has the potential to detect low levels of parasitemia, identify mixed infections, and allow for precise differentiation of species via melting curve analysis or TaqMan fluorescence-labeled probes. Since the first study published in 2001 at least 17 assays have been developed, most of them using SSUrRNA as the target gene. We used qPCR to detect Plasmodium falciparum and P. vivax by amplification of mtDNA; this technique was evaluated on whole-blood samples from people living in areas of malaria transmission in the Brazilian Amazon region located in the area of inclusion of highway BR-163 (Cuiabá-Santarém) in Pará State: São Luiz do Tapajós, a municipal district of Itaituba (N = 74); Três Boeiras, a municipal district of Trairão (N = 134), and São Raimundo, a municipal district of Aveiro (N = 62). The results from the real-time PCR-based method were compared to conventional microscopy and to an established mtDNA-PCR assay. The qPCR (mtDNA) method was 16-19 times more efficient than the conventional PCR (mtDNA) and microscopy for detecting plasmodial infections.