Quality assessment of malaria microscopy in Ouagadougou laboratories, Burkina Faso: accuracy of thick and thin blood smears

Abstract

Abstract Background Malaria microscopy remains the reference method for parasite detection in many low-resource settings, but its accuracy depends on slide preparation, staining quality, and reader performance. Objective This study aimed to assess the accuracy of routine malaria microscopy in selected laboratories in Ouagadougou, Burkina Faso. Methods We conducted a cross-sectional study in four laboratories in Ouagadougou, Burkina Faso, and re-examined 1,000 malaria blood smears initially read by 29 laboratory providers using independent expert microscopy. Results Twenty-nine microscopy providers participated, of whom 79.3% were biomedical technicians, 17.2% trainees, and 3.4% biologists. Routine microscopy classified 184/1000 slides (18.4%) as positive and 816/1000 (81.6%) as negative, whereas expert re-reading identified 115/1000 (11.5%) as positive and 885/1000 (88.5%) as negative. Overall concordance was 88.1%, with a sensitivity of 78.3%, specificity of 89.4%, positive predictive value of 48.9%, and negative predictive value of 96.9%. Inaccurate routine readings were significantly associated with lack of refresher training and shorter slide-reading time. Conclusion Routine malaria microscopy performance in the participating laboratories was limited by false-positive readings, highlighting the need for strengthened quality assurance and continuous competency-based training.