Comparative evaluation of BinaxNOW^™ Malaria rapid diagnostic test, microscopy and polymerase chain reaction for <i>Plasmodium falciparum</i> detection among individuals suspected with malaria in Lagos, southwest Nigeria

Abstract

Malaria is a major public health problem in the tropics, especially in resource-limited settings where presumptive malaria treatment is well practised. Prompt malaria diagnosis is essential in ensuring definitive antimalarial therapy. Malaria rapid diagnostic tests (mRDTs) are a suitable option in resource-limited settings. The study evaluated and compared the diagnostic performance of BinaxNOW™ mRDT, microscopy and quantitative polymerase chain reaction (qPCR) in suspected malaria cases in Lagos, south-western Nigeria. The cross-sectional study was conducted in four Primary Health Centres and Ikorodu General Hospital in Lagos. A total of 146 suspected malaria patients aged 2 to 67years were screened between August 2013 and November 2013. Venous blood samples were collected after informed consent was obtained from participants or guardians for mRDT, thick blood film for microscopy and dried blood spots on filter paper for PCR assays. Sociodemographic information of each patient was collected with a structured case report form. The sensitivity, specificity, positive and negative predictive values, diagnostic accuracy, and kappa’s level of agreement were analysed. The level of statistical significance was set at ρ ≤ 0.05. Falciparum malaria positive rate and prevalence were temperature (56.8%) and age-dependent (42.5%). The sensitivity and specificity of mRDT and microscopy were 94.7%, 91.7% and 85.4%, 96.5% respectively. While the positive predictive value (PPV) and negative predictive (NPV) were 79.9%, 94.2% and 96.4%, 95.0%. The diagnostic accuracy and kappa’s level of agreement for mRDT and microscopy were 89.0%, 94.5% and 0.78 and 0.89, respectively. The performance of BinaxNOW™ malaria RDT was comparable with microscopy and can be used to guide malaria treatment in resource-limited settings to enhance parasite-based treatment of all suspected malaria cases when microscopy is unavailable.