Performance Evaluation of Malaria Rapid Diagnostic Tests Available in the Nigerian Market: An In-Vitro Assessment at NIMR Lagos, South West Nigeria

The proliferation of malaria rapid diagnostic tests in the Nigerian market necessitates rigorous performance evaluation to ensure that products in use meet minimum sensitivity and specificity standards for public health impact. This study evaluated the performance characteristics of five commercially available malaria RDT brands against expert microscopy at the Nigerian Institute of Medical Research, Lagos, South West Nigeria. Archived blood samples from 300 confirmed and classified malaria cases and non-malaria febrile patients were used as a panel. Each RDT was tested by trained evaluators blinded to microscopy results. Sensitivity, specificity, positive predictive value, negative predictive value, and false-negative rate at low parasite density below 200 parasites per microlitre were calculated. Performance varied substantially across products. Two RDT brands met WHO recommended performance benchmarks with sensitivity above 95% and specificity above 90%. Two brands failed sensitivity standards at parasite densities below 200 parasites per microlitre, detecting only 74.2% and 67.8% of positive cases. Invalid rate was highest for one brand at 7.3%. Heat stability was acceptable for all brands at 35 degrees Celsius. The study identifies significant performance disparities among available malaria RDTs and recommends rigorous pre-procurement performance evaluation by NAFDAC, withdrawal of underperforming brands, and regular in-country lot testing of all malaria diagnostic products used in Nigerian public health programmes. Keywords: malaria RDT, performance evaluation, sensitivity, specificity, NAFDAC