Project Lead(s): Shana Kelley
Malaria accounts for more than 40% of outpatient visits in Tanzania and approximately 60,000 deaths each year. Early, accurate detection is critical to improving patient outcomes and monitoring outbreaks.
Current molecular detection technologies are not suitable for widespread, decentralized testing: lateral flow assays using antibody/antigen detection are not sufficiently sensitive; PCR requires costly and energy-intensive thermocycling; and enzymatic approaches require sample purification and sensitive reagents.
The project sought to address the need for multiplexed sample analysis of malaria by developing a highly sensitive molecular assay that is low cost and portable, using electrochemical sensors packaged in a disposable wand.
The assay quantifies unprocessed blood to detect infectious agents, such as the Plasmodium species that infect humans.
The direct detection of nucleic acids is integrated with a reagent-free, two-stage lysis method for red blood cells and malarial protozoa.
Detection of malaria is accomplished through probes directed towards malaria-specific genes and nucleic acids, and uses the multiplexing capabilities of the assay to provide strain-specific detection.
The device will also provide a molecular analysis for the presence of atovaquone resistance, to improve treatment for the drug-resistant strains of malaria parasite.
The team successfully developed the components necessary to develop a prototype device of a low-cost, hands-free molecular assay for diagnosis of infectious agents (such as malaria) in clinical samples.
The components are a low-cost sensor chip, a highly sensitive genotype-specific assay and a hands-free testing and read-out system suitable for low- and middle-income countries.
The team conducted an initial validation of the prototype assay and devices using synthetic/purified nucleic acids and achieved a clinically meaningful sensitivity of detection.
A novel read-out that transduces the results of an electrochemical assay into an easily interpretable visual indicator has also been developed.
The grant allowed for leveraging of the Genomic Applications Partnership Program, as administered through Genome Canada, the Ontario Genomics Institute, and the Ontario Research Fund for a total project funding of $6 million CAD.
This program provided the additional funding to fully develop the necessary technology for designing and fabricating the cost-effective prototype devices.
In addition, funding enabled the team to secure a partnership with a Canadian start-up, Xagenic Inc., for the development of low-cost diagnostics for infectious diseases.
This partnership has provided financial assistance to the project, as well as guidance on project planning and execution. Ongoing interactions between Xagenic staff and University of Toronto researchers have greatly enhanced the overall outcome of the project.