Abstract
BackgroundThe malaria rapid diagnostic tests (RDTs) are now widely used in the world. Compared to Plasmodium falciparum, a poor sensitivity of RDTs was reported against Plasmodium vivax based on the adopted antibody against pan-Plasmodium antigen lactate dehydrogenase (pLDH) or aldolase. Levels of pLDH were measured from patient with P. vivax, and the correlations between the levels of pLDH and the sensitivities of RDTs were analysed among Republic of Korea (ROK) isolates.MethodsThree RDTs, OptiMAL test, SD BIOLINE Malaria Ag P.f/Pan test, Humasis Malaria Pf/Pan antigen test, and the Genedia pLDH antigen ELISA were performed with blood samples from 152 febrile patients and 100 healthy controls.ResultsThree malaria RDTs revealed sensitivities between 85.5 (131/152) and 86.8% (132/152) with highest sensitivity for the detection of P.vivax by pLDH antigen ELISA test (145/152, 95.4%) in comparison to traditional microscopy using Giemsa–stained slides. None of the healthy control tested positive by three RDTs or ELISA, indicating 100% specificity in their respective test. Levels of pLDH among Korean P. vivax isolates ranged between 0 ng/mL and 22,387.2 ng/mL (mean ± standard deviation 3,917.5 ± 6,120.9 ng/mL). The lower detection limits of three RDTs were between 25 and 50 ng/mL with artificially diluted samples. The moderate degree of correlation was observed between parasitaemia and concentrations of pLDH (r = 0.4, p < 0.05).ConclusionThe pLDH levels of P. vivax are the main explanation for the variations in the performance of pLDH-based RDTs. Therefore, comparing sensitivities of RDT may need to include targeted biomarker value of patients.
Highlights
The malaria rapid diagnostic tests (RDTs) are widely used in the world
While sensitivities of currently available malaria assay kits in the market would fluctuate by field conditions, relatively poor sensitivities of RDTs for Plasmodium vivax with reactive antibodies to pan-Plasmodium antigen lactate dehydrogenase or aldolase was reported in comparison to RDTs for P. falciparum [2,6,7,8]
Major Plasmodium antigen lactate dehydrogenase (pLDH) levels of P. vivax (38.8%, 59/152) fell between 500– 5,000 ng/mL, and the second frequent level was over 5,000 ng/mL (25.1%, 40/152)
Summary
Compared to Plasmodium falciparum, a poor sensitivity of RDTs was reported against Plasmodium vivax based on the adopted antibody against pan-Plasmodium antigen lactate dehydrogenase (pLDH) or aldolase. The major target antigens of malaria RDTs were specific histidine-rich protein 2 (PfHRP-2), and Plasmodium lactate dehydrogenase in Plasmodium falciparum and pan-specific Plasmodium lactate dehydrogenase and aldolase were used for detecting other human Plasmodium species. While sensitivities of currently available malaria assay kits in the market would fluctuate by field conditions, relatively poor sensitivities of RDTs for Plasmodium vivax with reactive antibodies to pan-Plasmodium antigen lactate dehydrogenase (pLDH) or aldolase was reported in comparison to RDTs for P. falciparum [2,6,7,8]. The sensitivity of malaria RDTs depended usually on parasitaemia of patients, a common discrepancy was observed in treatment monitoring cases with gametocytaemia [9]. Monitoring the treatment outcomes through pLDH-based tests could be limited [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
