Globally, the World Health Organisation estimates three million undetected tuberculosis (TB) cases each year. These patients are referred to as the “missing millions.” In a state-of-the-art study, researchers examined a dielectrophoresis-based diagnostic tool that could enhance TB diagnosis and patient care in high-endemic, under-resourced locations. Providing diagnostics to people who require them the most can assist in achieving worldwide goals to lessen the burden of TB. The Journal of Molecular Diagnostics publishes the study’s findings.
An opportunity to prioritize the development of a low-cost, quick, accurate, and portable TB diagnostic test to examine sputum samples from suspected TB patients for Mycobacterium tuberculosis (Mtb) was presented by an innovative industry-academia collaboration between the TB research group at the St George’s University of London, the Institute for Infection and Immunity, and QuantuMDx, a medical technology business based in the UK.
The St. George’s University of London’s Philip D. Butcher, Ph.D., lead researcher, stated, “The worldwide incidence of TB is not improving. Despite being contagious, it is very treatable. To find the “missing millions,” however, affordable diagnostics that can be used at the point of care are required. Our TB research team at St George’s has long recognized the need for better TB diagnoses worldwide, and we concluded that cutting-edge technologies might provide the solution.
We recognized an opportunity by working together on a novel chip-based technique that uses dielectrophoresis to separate Mtb bacilli from sputum samples specifically. Dielectrophoresis, a little-used technique that may be modified to selectively attract or repel particular particles or cells based on their dielectric properties, is the basis of CAPTURE-XT technology. The remaining components of the sputum are washed away, leaving just the Mtb bacteria that cause TB to be selectively collected and concentrated.
The prototype’s performance was evaluated after optimization using a panel of 50 characterized sputum samples, utilizing a blinded screening of 100 characterized and bio-banked sputum samples provided by the Foundation for Innovative New Diagnostics (FIND).
To substitute the lab-based sputum smear/microscopic techniques, which usually have low rates of detection and need training workers in laboratories, at molecular-like sensitivities and a fraction of the cost, this chip-based technology takes advantage of the biological property of TB microbes to be specifically gathered onto the device so that small numbers can be visualized on the chip electrodes and act as a visual readout. When utilized as the front end to upstream cellular, protein, and molecular devices, the possibilities are endless.
Before COVID-19, TB was the most significant infectious disease-related cause of mortality, killing more people than malaria and HIV combined. TB is now the 13th leading cause of death globally. Globally, it infects 10 million people and kills 1.4 million annually, 230,000 of whom are children. Diagnostics with greater sensitivity and broader drug susceptibility testing are also required to combat drug resistance and diagnosis instances with a low bacterial burden.
