Comparison of performance characteristics of two malaria rapid diagnostic tests in detecting malaria infection among febrile patients in Urban Area of Lagos, Nigeria

Abstract

Antigen-based malaria rapid diagnostic tests (mRDT) play an important role in confirmation of malaria cases in all levels of healthcare in Nigeria because they are fast, easy to perform, and do not require special equipment or electricity. This study aimed at assessing the performance of two mRDTs in detecting histidine-rich protein 2 antigen in blood and urine of persons with uncomplicated falciparum malaria. Malaria parasite microscopy was the malaria diagnosis gold standard in this study. Matched blood and urine samples from 1,026 febrile persons were tested with two commercially available malaria antigen-detecting kits (SD Bioline and First Response^® ). Based on blood samples, similar malaria positivity rates were obtained by microscopy 181 (17.6%), SD Bioline 186 (18.1%) and First Response^® 183 (17.8%). Detection of HRP2 antigens in urine was  significantly lower than  HRP2 detection in blood (P<0.001) regardless of brand of mRDT used [SD Bioline (5.2% vs 18.1%) and First  Response^® (4.6% vs 17.8%)]. The performance characteristics of SD Bioline and First Response^® using blood samples were similar (P>0.05): sensitivity 96.7% vs 95.0%; specificity 98.7% vs 98.7%, Positive Predictive  Value (PPV) 92.5% vs 94% and Negative Predictive Value (NPV) 99.3% vs 86.4%. SD Bioline and First  Response^® HRP2 in urine and blood by the two kits was not dependent on the level of parasitaemia. The performance of the two brands of mRDTs in detecting HRP2 in whole blood and urine were similar (P>0.05). The two kits serve as good alternatives to malaria microscopy. The high NPV of both kits with urine specimen indicates that urine has the potential to be used for malaria but is not currently recommended to be used on blood-based malaria test kits.

Keywords: Histidine Rich Protein^® 2, Malaria Rapid Diagnostic Test, Performance characteristics, Urine.