Comparative Performance of Four Rapid Diagnostic Tests Kits, Microscopy and PCR in Asymptomat-ic Malaria Detection among Children from Ilishan-Remo Community, Southwest Nigeria

Background: Active malaria parasite detection is essential for effective malaria control and elimination in endemic settings. Asymptomatic malaria is often not detected and serves as a parasite reservoir for continuous malaria transmission. This study evaluated the comparative performance of four RDT kit brands, microscopy, and PCR to detect asymptomatic infection among children from the Ilishan-Remo community in Ogun state, southwest Nigeria. Methods: A cross-sectional study design was carried out to actively detect asymptomatic parasitaemia in children aged 3 months to 10 years during the dry season (November and December, 2022). Finger prick blood samples were collected for rapid diagnostic tests using SD-BiolineTM, Micro-pointTM, CarestartTM, and First-ResponseTM. Thick blood smears were prepared for microscopy, and dried blood spots for PCR analysis. The performance of the diagnostic methods was compared. Results: Of the 163 samples analysed, parasite positive rate as detected by PCR was 34 (20.9%), microscopy 38 (23.3%), SD-BiolineTM 19 (11.7%), Micro-pointTM 20 (12.3%), CareStartTM 25 (15.3%), and First-ResponseTM 23 (14.1%) respectively. The Sensitivity was 45.5%, 50.0%, 56.2%, 51.5%, and 70.0% for SD-BiolineTM, Micro-pointTM, CareStartTM, First-ResponseTM, and microscopy (p = 0.000), while specificity was 96.9%, 97.7%, 94.4%, 95.2% and 91.9% (p = 0.116) respectively. There was a significant statistical difference in the PPV (p = 0.037), while the NPV, accuracy, and kappa (k) were statistically not significant. Conclusion: Microscopy has shown a higher sensitivity and positive predictive value than rapid RDTs in detecting asympto-matic parasitaemia compared with PCR. This underscores the need for developing ultra-sensitive, cost-effective, and point-of-care diagnostic tools. Such tools could significantly enhance the control and elimination of malaria by actively detecting asymptomatic infection and reducing the parasite reservoir and malaria burden in Nigeria.