Performance of a novel melting curve-based qPCR assay for malaria parasites in routine clinical practice in non-endemic setting

• Published in: Malaria journal Vol. 22; no. 1; p. 191
• Main Authors: van Bergen, Kim J M, Stuitje, Antoine R, Akkers, Robert C, Vermeer, Henricus J, Castel, Rob, Mank, Theo G
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 22-06-2023; BioMed Central; BMC
• Subjects: Clinical medicine; Dehydrogenases; Deoxyribonucleic acid; Diagnosis; Diagnostic tests; DNA; Evaluation; Hospitals; Human diseases; Humans; Laboratories; Malaria; Malaria - diagnosis; Malaria - parasitology; Malaria, Falciparum - diagnosis; Malaria, Falciparum - parasitology; Melting; Melting curve; Melting curve analysis; Microscopic analysis; Microscopy; Microscopy - methods; Mitochondrial DNA; Parasitemia - diagnosis; Parasitemia - parasitology; Parasites; Patients; Performance evaluation; Plasmodium; Plasmodium falciparum - genetics; Polymerase chain reaction; Prevention; Public health; qPCR; Quantification parasitaemia; Sensitivity and Specificity; Species identification; Therapy-monitoring; Vector-borne diseases; Netherlands; United States > US; Germany; Plasmodium; Therapy-monitoring; Melting curve analysis; qPCR; Malaria; Quantification parasitaemia
• ISSN: 1475-2875; 1475-2875
• DOI: 10.1186/s12936-023-04617-z

High-quality malaria diagnosis is essential for effective treatment and clinical disease management. Microscopy and rapid diagnostic tests are the conventional methods performed as first-line malaria diagnostics in non-endemic countries. However, these methods lack the characteristic to detect very low parasitaemia, and accurate identification of the Plasmodium species can be difficult. This study evaluated the performance of the MC004 melting curve-based qPCR for the diagnosis of malaria in routine clinical practice in non-endemic setting.
Whole blood samples were collected from 304 patients with clinical suspicion of malaria and analysed by both the MC004 assay and conventional diagnostics. Two discrepancies were found between the MC004 assay and microscopy. Repeated microscopic analysis confirmed the qPCR results. Comparison of the parasitaemia of nineteen Plasmodium falciparum samples determined by both microscopy and qPCR showed the potential of the MC004 assay to estimate the parasite load of P. falciparum. Eight Plasmodium infected patients were followed after anti-malarial treatment by the MC004 assay and microscopy. The MC004 assay still detected Plasmodium DNA although no parasites were seen with microscopy in post-treatment samples. The rapid decline in Plasmodium DNA showed the potential for therapy-monitoring.
Implementation of the MC004 assay in non-endemic clinical setting improved the diagnosis of malaria. The MC004 assay demonstrated superior Plasmodium species identification, the ability to indicate the Plasmodium parasite load, and can potentially detect submicroscopic Plasmodium infections.