Simple, easy-to-use, low-cost nucleic acid amplification tests (NAATs) are not available for diagnosis of infectious diseases in low-resource settings (LRS). Challenges to easy adoption or modification of existing NAAT technologies for LRS use include time-consuming sample preparation;cold chain requirements for reagent storage;and lack of instrumentation, electricity, and training at the point of care. Unfortunately, there are many infectious diseases rampant in LRS where the lack of appropriate NAATs is a critical barrier to timely diagnosis and treatment. PATH proposes a collaborative effort with the CDC that simultaneously merges scientific and technological capabilities with this clinical need to develop a calcium oxide (CaO)-heated DNA amplification kit that obviates the requirements for electricity and instrumentation at the point of care. PATH has demonstrated the use of CaO for heat and a proprietary engineered phase change material to stabilize an assay mixture within a narrow temperature range suitable for isothermal amplification. The CDC has developed a novel combination of lysis buffer, loop mediated isothermal amplification (LAMP) reaction and fluorescently-labeled primers to enable a simplified, extraction-free and lysis-free workflow. These recent innovations can be combined with a simple two-chamber, high-containment reaction tube prefilled with lyophilized LAMP mixture to create the first electricity-free, instrument-free, easy-to-use, low-cost NAAT kit. We envision multiple NAAT kits customized and validated for specific strains of infectious diseases such as tuberculosis, malaria, and HIV that will advance evidence-based medical practice at the point of care in LRS. We will develop, integrate, and validate components of this NAAT kit with the sensitivity of PCR, the simplicity of a strip test, and sufficient stability for storage out of the cold chain for long periods of time.
Aims 1 and 2 below describe development of the kit components.
Aim 3 describes the integration of these components into a stand-alone kit designed for low-infrastructure use. Finally, Aim 4 proposes the laboratory validation of this kit using HIV-1, a highly relevant pathogen afflicting many populations in LRS. """""""" Aim 1: Specify and optimize the properties of the electricity-free incubator active materials using the existing incubator prototype. """""""" Aim 2: Optimize CDC's innovations to LAMP HIV-1 assay, establish dry reagent formulations, and define sample. """""""" Aim 3: Design and fabricate optimized kit hardware and consumables: the isothermal incubator and reaction containment tube. """""""" Aim 4: Validate the electricity-free and instrument-free assay kit created in Aims 1-3.
We propose to integrate two innovations to create and validate the first electricity-free, instrument-free, easy-to-use, low-cost, nucleic acid amplification test kit for diagnosis of infectious diseases in low-resource settings. PATH has demonstrated the use of calcium oxide and a proprietary engineered phase change material to stabilize the temperature of an assay mixture within a narrow range suitable for isothermal amplification. The Centers for Disease Control and Prevention have developed a novel combination of lysis buffer, loop mediated isothermal amplification (LAMP) reaction and fluorescently-labeled primers to enable a simplified, extraction-free and lysis-free workflow. These two technologies will combine with a simple, two-chamber, disposable, high containment reaction tube prefilled with lyophilized LAMP mixture.
