Evaluation of NxTek™ Eliminate Malaria-PF test and biocredit rapid diagnostic tests for detecting Plasmodium species in Southern Ethiopia

Abstract

Rapid diagnostic tests (RDTs) play an essential role in the prompt diagnosis of malaria in settings where using microscopy is not feasible. This study aimed to evaluate the diagnostic performance of NxTek™ Eliminate Malaria-Pf test, Biocredit RDTs Pf(pLDH/HRP2) and Pf/Pv(pLDH/pLDH) for the detection of Plasmodium species. A health facility-based cross-sectional study was conducted from September to November 2024 in 384 malaria-suspected febrile study subjects at Dilla Zuria health facility. Venous blood samples were collected for malaria diagnosis using microscopy, RDTs, and quantitative Polymerase Chain Reaction (qPCR). Sensitivity, specificity, positive/negative predictive value, and accuracy were calculated using microscopy and qPCR as reference standards. Using microscopy as the reference standard, the NxTek™ Eliminate Malaria-Pf test demonstrated a sensitivity of 87.6% and a specificity of 91.3% for the detection of P. falciparum. The Biocredit Pf/Pv (pLDH/pLDH) RDT exhibited a sensitivity of 97.9% and specificity of 97.4% for P. falciparum, and a sensitivity of 94.5% and specificity of 97.5% for P. vivax. The Biocredit Pf (pLDH/HRP2) RDT showed sensitivity and specificity values of 97.4% and 97.5%, respectively. In comparison, the SD Bioline RDT yielded a sensitivity of 51.3% and specificity of 93.2% for P. falciparum, and sensitivity and specificity of 86.3% and 96.5%, respectively, for P. vivax. When using quantitative PCR (qPCR) as the reference standard, the Biocredit Pf/Pv (pLDH/pLDH) RDT demonstrated a sensitivity of 95.5% and specificity of 96.4% for P. falciparum, and sensitivity and specificity of 90.8% and 99.1%, respectively, for P. vivax. The Biocredit RDTs outperformed conventional RDTs in both sensitivity and specificity and met the World Health Organization’s (WHO) diagnostic criteria. These results support their utility in routine malaria diagnosis, particularly in resource-limited endemic settings.