High-Sensitivity Near Point-of-Care Detection of Asymptomatic and Sub-microscopic Plasmodium Infections in African Endemic Countries

Abstract

ABSTRACT The limited diagnostic capacity to detect asymptomatic individuals with low parasite densities continues to hinder malaria elimination efforts across Africa. We adapted a near point-of-care LAMP-based diagnostic platform, originally designed for viral detection in respiratory and skin lesion specimens, for malaria diagnosis using capillary blood. The resulting Pan /Pf malaria test meets the Malaria Eradication Research Agenda (malERA) essential criteria for community-level malaria screening, with an analytical limit-of-detection of 0.6 parasites/μL and a sample-to-result turnaround time under 45 minutes. We evaluated the test using 672 capillary blood samples obtained via finger pricks from individuals enrolled at the community level in The Gambia and Burkina Faso, including 146 positives for P. falciparum confirmed by dried blood spot qPCR. The test achieved a sensitivity of 95.2% [95% CI: 90.4-98.1] and specificity of 96.8% [95% CI: 94.9-98.0]. It also detected 94.9% (130/137) of asymptomatic malaria infections and 95.3% (41/43) of sub-microscopic cases (<16 parasites/µL), outperforming expert light microscopy, which detected 70.1% (96/137) and 0% (0/43), and rapid diagnostic tests, which detected 49.6% (68/137) and 4.7% (2/43), respectively. This field molecular method represents a sensitive and scalable diagnostic solution with the potential to support test-and-treat strategies for malaria elimination across Africa.