Evaluating the use of microscopic examination and rapid diagnostic tests to diagnose malaria in North Central Nigeria

The global impact of malaria has spurred interest in developing prompt and accurate diagnostic strategies to provide an effective management of the disease. The aim of this study was to compare rapid diagnostic tests (RDTs) for malaria with routine microscopy. Samples were collected randomly from 364 febrile out-patients with clinical suspicion of malaria from four hospitals in North Central Nigeria. Results from the rapid diagnostic kits were analysed and compared to those obtained by general microscopy. Of the 364 out-patients involved in the study, 218 (59.89%) tested positive for Plasmodium falciparum by RDTs, whereas 263 (72.256%) tested positive by microscopy. There are significant differences (P<0.05) in infection rates between RDT and microscopy. The sensitivity, specificity and negative predictive values of RDTs compared to microscopy are low, while the positive predictive value is high. Evaluation of RDTs against the parasite-positive panel with parasite densities of <1000 parasites/μL, between 1000-5000 parasites/μL and above 5000 parasites/ μL was 11.73, 30.61, 57.65% for RDTs compared to 6.11, 27.95 and 65.94% for microscopy, respectively. Test line intensity increases with increase in parasite densities for both methods.