Project summary: Rapid Diagnostic Tests (RDTs) that detect the malaria parasite, Plasmodium falciparum (Pf) antigen – histidine-rich protein (PfHRP), account for more than 90% of malaria diagnosis in the world. However, over the past decade, there have been significant decline in the performance of PfHRP-based RDTs, including high false-negative rates for clinical Pf infections. This poor performance has been associated with marked increases (>40%) in the prevalence of Pf parasites with deleted Pfhrp2/3 genes, dubbed as ‘diagnostic-resistant parasites’, now a huge threat to global malaria control and elimination efforts. Therefore, WHO has recommended a switch to non-PfHRP2/3 tests in endemic regions where Pfhrp2/3-deleted Pf prevalence is above 5%. This study aims to develop a novel cost-effective nucleic acid isothermal amplification test that can detect Pfhrp2/3-deleted parasites, with comparable sensitivity to the more expensive PCR-based tests, and with utility for point-of-care malaria diagnosis and surveillance in resource-poor and remote settings.
Project Aim: Optimisation of isothermal amplification assays to detect and differentiate Pfhrp2/3-deleted parasites in clinical and asymptomatic Pf infections.
Objectives
1.1. Design and in silico validation of primers
1.2. Development of singleplex assays with fluorometric detection systems.
1.3. Optimisation of multiplex assays with fluorescent probes.
1.4. Evaluate the analytical performance of the optimised assays.
Expected outcomes: Proof-of-concept assay for analytical testing, to be published as a major manuscript.
Skills acquisition: Molecular biology skills including RT-PCR, assay design and optimisations. Genomics and Bioinformatics. Project management. Pre-clinical trials. Statistical analysis (STATA/SPSS) and programming in R.
Professional development: Networking with the malaria community in Melbourne (WEHI, Doherty, Burnet and Deakin University). Conference/Workshop attendances.
Project duration: 1 year; Jan-Dec 2024.
Supervision: Dr. Charles Narh and Prof. Alyssa Barry.
Contact: charles.narh@deakin.edu.au
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