Diagnosing infection levels of four human malaria parasite species by a polymerase chain reaction/ligase detection reaction fluorescent microsphere-based assay

• Published in: The American journal of tropical medicine and hygiene Vol. 74; no. 3; pp. 413 - 421
• Main Authors: MCNAMARA, David T, KASEHAGEN, Laurin J, GRIMBERG, Brian T, COLE-TOBIAN, Jennifer, COLLINS, William E, ZIMMERMAN, Peter A
• Format: Journal Article
• Language: English
• Published: Lawrence, KS Allen Press 01.03.2006
• Subjects: Animals; Aotidae; Biological and medical sciences; DNA, Protozoan - chemistry; DNA, Protozoan - genetics; Fluorescent Dyes - chemistry; Human protozoal diseases; Humans; Infectious diseases; Ligase Chain Reaction - methods; Malaria; Malaria - diagnosis; Malaria - parasitology; Malaria, Falciparum - blood; Malaria, Falciparum - diagnosis; Malaria, Falciparum - parasitology; Malaria, Vivax - blood; Malaria, Vivax - diagnosis; Malaria, Vivax - parasitology; Medical sciences; Microspheres; Parasitic diseases; Plasmodium; Plasmodium - genetics; Polymerase Chain Reaction - methods; Protozoal diseases; Regression Analysis; Sensitivity and Specificity; Human; Protozoa; Apicomplexa; Protozoal disease; Malaria; Monkey; Fluorescence; Parasitosis; Infection; Polymerase chain reaction; Plasmodium falciparum; Plasmodium vivax; Vertebrata; Experimental disease; Mammalia; Ligase chain reaction; Animal; Primates; Microorganism culture; Tropical medicine; Diagnosis; Molecular biology; Detection
• ISSN: 0002-9637; 1476-1645
• DOI: 10.4269/ajtmh.2006.74.413

Improving strategies for diagnosing infection by the four human Plasmodium species parasites is important as field-based epidemiologic and clinical studies focused on malaria become more ambitious. Expectations for malaria diagnostic assays include rapid processing with minimal expertise, very high specificity and sensitivity, and quantitative evaluation of parasitemia to be delivered at a very low cost. Toward fulfilling many of these expectations, we have developed a post-polymerase chain reaction (PCR)/ligase detection reaction-fluorescent microsphere assay (LDR-FMA). This assay, which uses Luminex FlexMAP microspheres, provides simultaneous, semi-quantitative detection of infection by all four human malaria parasite species at a sensitivity and specificity equal to other PCR-based assays. In blinded studies using P. falciparum-infected blood from in vitro cultures, we identified infected and uninfected samples with 100% concordance. Additionally, in analyses of P. falciparum in vitro cultures and P. vivax-infected monkeys, comparisons between parasitemia and LDR-FMA signal intensity showed very strong positive correlations (r > 0.95). Application of this multiplex Plasmodium species LDR-FMA diagnostic assay will increase the speed, accuracy, and reliability of diagnosing human Plasmodium species infections in epidemiologic studies of complex malaria-endemic settings.