Comparison of Microscopic Determination and Rapid Diagnostic Tests (RDTs) in the Detection of Plasmodium Infection

Abstract

Malaria infection is the most common diagnosis made in Africa. Efficient diagnosis of malaria parasite is very vital for treatment of malaria infection. The efficacy of rapid diagnostic tests (RDTs) in comparison to microscopy, the gold standard, in the diagnosis of malaria in Nigeria has not been fully ascertained. This study compared the sensitivity, specificity and predictive values of RDTs available in Nigeria market with microscopy. Two RDT kits were used and their results were compared with the gold standard, microscopy using thick and thin blood films (TBF and tBF). TBF had sensitivity of 85%, specificity of 30%, positive predictive value (PPV) of 55.2%, and negative predictive value (NPV) of 66.6%; tBF had sensitivity of 80%, specificity of 35%, positive predictive value (PPV) of 55.2%, and negative predictive value (NPV) of 63.6%. Among the RDTs, Care Start HRP 2 kit had sensitivity of 65%, specificity of 50%, positive predictive value (PPV) of 56.5%, and negative predictive value (NPV) of 59% while SD Bioline kit had sensitivity of 55%, specificity of 65%, PPV of 61%, and NPV of 59%. It can thus be inferred that rapid diagnostic test kits are not as sensitive as microscopy in diagnosis of malaria parasite, but they are more accurate and are thus suitable alternatives to microscopy.