Title : A platform for rapid, sensitive detection of aerosolized pathogens in exhaled breath and ambient indoor air
Abstract:
Respiratory infections are among the top two causes of treat-and-release Emergency Department (ED) visits in the USA. Globally, respiratory infections accounted for ~42.8% of all- cause illnesses in 2019. The combined forces of rapid urbanization, globalization, and easy international travel have heightened the risk of widescale transmission of respiratory infections, thereby posing an increased threat to public health. This strain became especially evident in the recent COVID-19 pandemic, which resulted in ~6.9 million deaths globally.
Aerosols are the primary route of disease transmission for the majority of respiratory diseases, yet technologies to directly detect aerosolized pathogens have been insufficient in speed or sensitivity to enable intervention. We have developed a platform biosensor technology to detect aersolized pathogens that enables new testing and monitoring strategies, with an initial focus on SARS-CoV-2.
The electrochemical sensor uses voltammetry to measure oxidation of tyrosine amino acids within a protein on the surface of the pathogen. Oxidation is the release of electrons that the carbon electrode detects as a change in current. The amount of current is proportional to the amount of protein present. The biosensor uses a llama nanobody (antibody) that is covalently attached to the surface to provide specificity and concentrate the protein at the electrode for measurement. The device collects an exhaled breath condensate on to a chilled hydrophilic surface.
We developed a breath-based diagnostic to rapidly detect SARS-CoV-2 from a single breath. Preliminary human data from COVID-19 patients collected through clinical trials conducted at the WUSTL Infectious Disease Clinical Research Unit (IDCRU) has demonstrated the feasibility and specificity of the technology in breath-based diagnosis. The time from breath into the device to read-out of infection is under 60 seconds. The biosensor detects all past and current strains of SARS-CoV-2 and is sensitive to 20 viral particles in a sample. The device can be multiplexed to detect multiple pathogens from a single breath on distinct electrodes. we have also developed an air biodetector to monitor the built environment for the presence of aerosolized pathogens. The air biotector can process samples every 5 minutes, and produce a readout in 17 seconds. We have demonstrated that the biodetector can determine the presence of a individual infected with SARS-CoV-2 with sufficient speed and sensitivity to enable interventions that serve to prevent the transmission of disease.
Rapid detection of a respiratory pathogen can be used in mass screening of individuals as they file into indoor spaces, such as airport security areas, office buildings, conference centers, mass transit hubs, or military vessels. Having test turnaround times of 60 seconds allows for large queues of individuals to be screened rapidly, then either admitted or quarantined away from the group. In addition, the breathalyzer could also be used in point-of-care (POC) locations, such as local clinics or pharmacies. The team at Washington University has worked in close conjunction with Varro Life Sciences with an eye on commercialization throughout the research and development phases.
