Journal Article

Clinical evaluation of a novel Mologic malaria Plasmodium falciparum LDH-dependent lateral flow rapid diagnostic test diagnostic accuracy: a cross-sectional study, Sudan

Mohammed, Fayad Osman, Mustafa, Sayed A., Chamai, Martin, Hamid, Muzamil M. Abdel, Jebreel, Waleed M. A., Elaagip, Arwa, Albsheer, Musab M., Mohamed, Abdelrahim O., Ahmed, Shaden B. A., Ahmed, Tarig M. E., Dittrich, Sabine

2025

Overview

Background Malaria diagnosis by Rapid Diagnostic Test (RDT) is challenged by the newly emerging histidine-rich protein 2 (HRP2) gene deletion in the Plasmodium falciparum species. The alternative lactate dehydrogenase (LDH)-dependent RDTs suffer from low sensitivity, and improvement in the sensitivity of LDH RDTs is the cornerstone for detecting the (HRP2) gene deletion species. This study aimed to evaluate a novel, improved Mologic Malaria Pf LDH-dependent RDT for the diagnosis of P. falciparum malaria in partnership with the Foundation for Innovative Diagnostics (FIND), Switzerland. Methods This is a descriptive cross-sectional study evaluating the clinical performance of the improved Mologic LDH- RDT in two rural sites in Khartoum state, Sudan. Five hundred patients presenting with symptoms suggestive of malaria in the two primary care health centres were enrolled after signing informed consent. Finger-prick blood was collected for examination with microscopy, the index Mologic LDH RDT, the comparator RDT, and preparation of DBS for PCR, the reference method. Results The mean age of the study subjects was 31 years, ranging from 5 to 80 years. Out of 500 patients, 210 (42%) were positive by PCR, 200 (40%) by expert microscopy, 193 (38.6%) by index Mologic LDH RDT, and 199 (39.8%) by comparator RDT. The sensitivities of microscopy, index RDT, and comparator RDT were 95.24% (95% CI, 91.4–97.6), 91.9% (95% CI, 87.3–95.2), and 93.81% (95% CI, 89.6–96.6), respectively. All tests were nearly 100% specific for the detection of P. falciparum parasites. The concordance test showed almost perfect agreement with the reference test ( κ  = 0.929). Six samples were P. falciparum HRP2 Ag negative and were detected by Mologic LDH RDT. A limitation of this study is that there is no confirmation of HRP2 gene deletion by PCR. Conclusion The novel Mologic LDH RDT showed performance concordant with standard expert microscopy and the comparator HRP2-based RDT. The sensitivity of the Mologic LDH RDT makes it suitable for the clinical management of P. falciparum HRP2 negative malaria.

• Publisher: BioMed Central,BioMed Central Ltd,BMC
• Subject: Adolescent / Adult / Aged / Aged, 80 and over / Anopheles / Antigens, Protozoan / Biomedical and Life Sciences / Biomedicine / Child / Child, Preschool / Clinical evaluation / Cross-Sectional Studies / Diagnosing the Data: Malaria RDT Recording and Reporting Accuracy in Four African Countries and Implications for Surveillance / Diagnosis / Diagnostic accuracy / Diagnostic Tests, Routine - methods / Entomology / Evaluation / Female / Field testing / Humans / Identification and classification / Infectious Diseases / L-Lactate Dehydrogenase / Lateral flow / LDH, Rapid diagnostic test / Malaria / Malaria, Falciparum - diagnosis / Male / Microbiology / Middle Aged / Molecular diagnostic techniques / Parasitology / Plasmodium falciparum / Plasmodium falciparum - enzymology / Plasmodium falciparum - isolation & purification / Protozoan Proteins - genetics / Public Health / Rapid Diagnostic Tests / Sensitivity and Specificity / Sudan / Tropical Medicine / Young Adult