Meta-analysis of the diagnostic performance characteristics of three commercial and one in-house nucleic acid amplification tests for malaria screening

Abstract

Abstract Background A meta-analysis of previously performed evaluation studies of nucleic acid amplification testing (NAT) approaches for the screening for and differentiation of Plasmodium spp. using identical samples was performed to comparatively assess their suitability for the routine diagnostic setting. Methods Three commercial NATs for malaria (one loop-mediated isothermal amplification [LAMP] assay, two real-time polymerase chain reactions [PCRs]) and one in-house real-time PCR were comparatively assessed with a collection of 1020 well-characterized ethylenediaminetetraacetic acid (EDTA) blood samples from patients with suspected or confirmed malaria. Results Altogether 765 (75%) concordantly negative and 223 (21.9%) concordantly positive results of the four molecular tests were obtained, while discordant results were seen in 32 (3.1%) instances. For genus-specific assays, the observed sensitivity and specificity ranges were 96.4%–98.4% and 99.6%–99.9%, and for species-specific assays, 94.0%–97.6% and 99.6%–100%, respectively. Falsely negative molecular test results comprised microscopically negative samples, samples at the microscopic detection threshold and quantitatively less abundant species in mixed infections. Conclusions Excellent test characteristics of all assessed assays with only minor differences encourage molecular malaria screening with genus- and species-specific NAT with discrepancies only within the borderline range of their detection thresholds.