New Delhi, Sep 17 : From the currently used sputum testing, soon tuberculosis screening can be done via a simple tongue swab, according to a study.

The potential breakthrough using an enhanced CRISPR-based technology could allow easier, community-based screenings for the world's deadliest infectious disease, said researchers from Tulane University in the US.

Lead author Zhen Huang, an assistant professor at Tulane's School of Medicine, said developing a viable tuberculosis tongue swab test could transform testing in low-resource communities.

"Tongue swabs are painless, easy to collect, and don't require trained medical staff," Huang said. "That opens the door to large-scale screenings."

Current TB tests rely on sputum; mucus collected from the lungs and lower respiratory system.

Collecting sputum is not only difficult but is also unfeasible in about 25 per cent of symptomatic cases and nearly 90 per cent of asymptomatic cases -- a gap which contributes to an estimated 4 million tuberculosis cases going undiagnosed annually.

The study, published in the journal Nature Communications, worked to address that gap by refining a previously developed CRISPR-based assay to better detect TB in samples with very low levels of bacteria, such as stool, spinal fluid, and tongue swabs.

The new CRISPR method, called the ActCRISPR-TB, increased amplification and detection of genetic signals from TB bacteria DNA and offered a rapid, streamlined approach that can return a diagnosis in under an hour.

Clinical testing showed markedly enhanced detection of TB in tongue swabs over traditional testing (74 per cent compared to 56 per cent).

The test also showed high sensitivity in detecting TB in respiratory (93 per cent), pediatric stool (83 per cent), and adult spinal fluid samples (93 per cent).

With children, HIV patients, and those with extrapulmonary TB unable to produce sputum, the research marks a significant step forward toward offering effective diagnoses via a variety of samples.

/IANS