Comparative Evaluation of Microscopy, Rapid Diagnostic Tests, and Polymerase Chain Reaction (PCR) for Malaria Diagnosis in Nigerian Children.

Background  Malaria, a persistent public health issue in Nigeria, particularly among children, is often complicated by misdiagnosis, hindering effective treatment and control. The global adoption of rapid diagnostic tests (RDTs) for malaria has significantly improved management. This study, therefore, compares the diagnostic performance of microscopy, RDT, and polymerase chain reaction (PCR) for Plasmodium falciparum detection in children in Kano state, Nigeria, providing crucial insights for effective control and elimination. Methods Capillary blood samples and dried blood spots (DBS) were collected from 200 febrile children in a selected health center in Kano and systematically tested using RDT, microscopy, and nested polymerase PCR. The sensitivity and specificity for each diagnostic method were calculated, with nested PCR as the reference to assess diagnostic accuracy. Structured questionnaires were used to obtain information on possible risk factors. Data were analyzed using univariate, bivariate, and multivariate analysis, with p<0.05 considered significant. Results Out of the 200 children enrolled in the study, 112 (56%) tested positive by microscopy, 60 (30%) by RDT, and 70 (35%) by PCR. Using PCR (n=70) as the reference test, microscopy demonstrated a sensitivity of 73% and a specificity of 53%, while the RDT exhibited a lower sensitivity of 27% but a higher specificity of 68%. False positivity rates of 22 (31.5%) for RDT and 33 (46.9%) for microscopy were observed. Regarding false negatives, RDT had a much higher rate of 51 (72.9%) than microscopy of 19 (27.1%). Conclusion The study divulges the limitations of RDT in malaria detection, particularly its low sensitivity. With its higher sensitivity, microscopy also showed a significant false-positive rate. The study suggests a practical solution combining RDT and microscopy for routine malaria diagnosis, which could significantly improve diagnostic accuracy. More ongoing research is needed to develop more suitable RDTs for routine malaria diagnosis in endemic communities.