Evaluation of malaria diagnoses using a handheld light microscope in a community-based setting in rural côte d'Ivoire

Abstract

Portable microscopy may facilitate quality diagnostic care in resource-constrained settings. We compared a handheld light microscope (Newton Nm1) with a mobile phone attachment to conventional light microscopy for the detection of Plasmodium falciparum in a cross-sectional study in rural Cote d'Ivoire. Single Giemsa-stained thick blood film from 223 individuals were prepared and read by local laboratory technicians on both microscopes under 1,000× magnification with oil. Of the 223 samples, 162 (72.6%) were P. falciparum positive, and the overall mean parasite count was 1,392/μL of blood. Sensitivity and specificity of the handheld microscope was 80.2% (95% confidence interval [CI]: 73.1-85.9%) and 100.0% (95% CI: 92.6-100.0%), respectively, with a positive and negative predictive value of 100.0% (95% CI: 96.4-100.0%) and 65.6% (95% CI: 54.9-74.9%), respectively. If sensitivity can be improved, handheld light microscopy may become a valuable public health tool for P. falciparum diagnosis.