Pioneering new research revolutionises early detection of TB

Researchers at the University of Leicester and the University of Pretoria are revolutionising the way tuberculosis (TB) is diagnosed through the invention of a 3D printed insert added to a simple face mask, which has the potential to save millions of lives across the world every year through early detection of the disease.

Designed and printed at the University, the insert can reliably catch and retain live tuberculosis bacteria, after a patient who may have symptoms has worn it for thirty minutes. In comparison, current diagnosis of TB can take weeks.

Unlike a blood test, which cannot differentiate between active and dormant TB, the mask provides rapid detection of bacteria, offering a more direct indicator of how infectious individuals are compared to traditional sputum samples, reducing the need for invasive investigation.

TB is the largest infectious cause of death globally, affecting up to 6,000 people in the UK every year and more than 10 million people worldwide.

Professor Mike Barer at the University of Leicester said: “This is the first time that exhalation from prospective patients with TB can be captured in such a quick and simple way. This pioneering research provides the opportunity to save thousands of lives every year across the world by early detection of a treatable disease – it’s world-changing.

“The fact that the mask is a low cost and more accurate option for detecting live TB before it appears in sputum has huge implications for early detection of the disease and patients having earlier access to treatment. We are really excited about how we can take this forward and influence the spread of airborne infection."

It costs the NHS £1.8m annually to test for TB in adults (NICE data) – in comparison, the mask insert materials cost around £2 to print, potentially saving thousands for the health service.

The findings, published online on The Lancet website on Tuesday 18 February 2020, have the potential to revolutionise the opportunity for early detection and prevention of the disease.

Researchers worked in conjunction with research team at the University of Pretoria in South Africa, initially sampling 24 people with confirmed TB during a 24 hour period, which showed that infectious TB was exhaled and spread when patients were asleep – a breakthrough in our understanding of the disease, demonstrating that a cough may not be required to spread the infection.

The trial showed 86.5% of the patients testing positive for TB through the use of the mask, and only 20.5% from sputum - despite all patients being positively tested for TB through sputum at the start, demonstrating the reliability of the mask for achieving consistent results.

In addition, a further trial of 20 patients with TB symptoms, four patients with negative sputum tested positive with the mask, and the presence of TB was only detected in their sputum after the six weeks later – demonstrating the accuracy of the test and highlighting the potential for early diagnosis.

One of the most common symptoms of the disease is a persistent cough with phlegm. TB is usually diagnosed with a blood test, chest x-ray, phlegm sample and in some cases a bronchoscopy. Often when these symptoms present, the infection has already been in the body for a few weeks already and the person may have infected many others. This is especially important in developing countries, where people with HIV are at higher risk.

Professor Barer continued: “The mask insert has the potential to save millions of lives globally, being easily accessible and cost effective to produce.”

• Exhaled Mycobacterium tuberculosis output and detection of subclinical disease by face-mask sampling: prospective observational studies doi:10.1016/S1473-3099(19)30707-8