Detection of Plasmodium falciparum Directly from Blood Samples Using the Polymerase Chain Reaction.

Malaria remains one of the major causes of human morbidity and mortality, particularly in some developing countries such as iran. the importation of malaria also into a place or region where they are not endemic raises many concerns, including the timely delivery of appropriate care, safety of the blood supply, the risk of autochthonous and transmission. although different methods are appli-cable for detection of parasites which cause malaria, some of them do not have enough sensitivity. in this study a direct polymerase chain reaction (pcr) and light microscopy approaches were compared to detect plasmodium falciparum in terms of sensitivity and specificity using blood samples from people with malaria-like symptoms and fever. a target dna sequence of the plasmodial 18s ribosomal dna (206 bp) was amplified by pcr. the assay showed a threshold of parasite density (detection limit) of one p. falciparum parasite/20microliter. matching results were obtained for 18 people who presented malaria-like symptoms and fever. our results showed that the direct pcr method proved to be a more sensitive and useful tool than the light microscopy assay to determine p. falciparum. microscopy assay showed a low sensitivity (37.3%) when compared with falciparum-dna detection by direct pcr (87.5%). in conclusion it was determined that direct pcr is a reliable method for detection of malaria parasites and it may be a useful tool for detection of other parasites as well.