Ultrasensitive molecular tests for Plasmodium detection: applicability in control and elimination programs and...

Area of Science:

• Molecular diagnostics
• Parasitology
• Infectious diseases

Background:

• Accurate detection of malaria parasites is crucial for effective control and elimination strategies.
• Low-level parasitemia and diverse Plasmodium species present diagnostic challenges.

Purpose of the Study:

• To evaluate the performance of two molecular assays, RealStar® Malaria PCR Kit 1.0 (alt-Gen) and RealStar® Malaria Screen & Type PCR Kit (alt-S&T), for detecting low-level Plasmodium parasitemia.
• To assess their utility in identifying all five human-infecting Plasmodium species for malaria control programs and reference laboratories.

Main Methods:

• Evaluation of 145 blood samples using alt-Gen and alt-S&T kits.
• Comparison of results with nested polymerase chain reaction (nPCR), quantitative PCR (qPCR), and thick blood smear microscopy.
• Analysis of sensitivity, specificity, and correlation of cycle threshold values.

Main Results:

• The alt-S&T assay demonstrated 100% sensitivity for most Plasmodium species, with 93.94% for P. falciparum, compared to nPCR.
• Both alt-Gen and alt-S&T showed high sensitivity and significant correlation with qPCR (r=0.8621 and r=0.9371, respectively).
• These molecular assays detected submicroscopic infections in asymptomatic individuals, which were missed by thick blood smear.

Conclusions:

• The alt-Gen and alt-S&T assays are suitable for detecting submicroscopic malaria infections.
• These tools can aid in epidemiological surveys, reference laboratory diagnostics, and blood bank screening.
• Their implementation supports global malaria elimination efforts.