Easy-to-obtain 'oral swab' samples can be game changer for TB control

A team of researchers has developed new approach to diagnosing tuberculosis (TB) with easy-to-obtain oral swab samples.

Researcher Gerard Cangelosi said that care and control of the disease TB really requires prompt case-finding and detecting the disease with a simple oral swab could be a game changer for TB control because it could make diagnosis cheaper and easier.

TB claims more lives each day than the cumulative toll of the Ebola outbreak. Diagnosing TB conventionally involves collecting and testing a person's sputum, the thick, gluey mucus coughed up from the lungs.

Working with sputum samples is challenging due to the material's "horribly gloppy" nature, as Cangelosi called it. Sputum can hide pathogens from pathologists because it is difficult to dislodge bacteria from within the mucus' milieu. Also, in order to produce sputum, patients must cough, which puts sample-collecting public health workers at risk for contracting the disease.

Previous efforts to test for TB in materials other than sputum, such as blood, urine or exhaled breath, have been limited by much lower accuracy, with detection rates typically below 50 percent.

Moreover, safely obtaining blood or urine samples requires specialized certification, whereas volunteers with minimal training may collect oral swabs. This could open the door to widespread implementation of this new approach.

A long-term goal is to enable active TB case finding, in which at-risk populations are actively screened for the disease to identify and prevent opportunities for transmission.

Cangelosi stressed that the study is merely a proof of principle, limited by its small size. Efforts are under way to expand this initial study into a large-scale controlled trial. Yet the preliminary success offers hope for greatly improved TB detection and control, especially in nations with limited public health resources.

The work is published in Scientific Reports.