Non-invasive diagnosis of tuberculosis using respiratory masks
New diagnostic procedure: Genetic material from tuberculosis bacteria detected in respirator masks worn by patients with pulmonary tuberculosis.
Diagnosis of pulmonary tuberculosis (TB) has so far been based primarily on sputum samples. However, not all patients are able to produce sufficient sputum. A recently published prospective study shows that face mask sampling (FMS) could be a promising, non-invasive addition to existing diagnostic methods. The results were published in the journal Clinical Microbiology and Infection.
The study was conducted at the IMSP "Chiril Draganiuc" Institute of Pneumology in Chișinău, Republic of Moldova, under the direction of Assoc. Prof. Dumitru Chesov and Dr. Thomas Theo Brehm at the Research Center Borstel, Leibniz Lung Center, in collaboration with local partners. For this purpose, the first author, medical student Dariusz Wölk from the University Medical Center Hamburg-Eppendorf, traveled to Chișinău for a year. His doctoral thesis was funded by an MD scholarship from the DZIF Academy of the German Center for Infection Research (DZIF).
A total of 117 adult patients with suspected or confirmed pulmonary tuberculosis were examined over the course of a year. During face mask sampling, participants wore specially adapted FFP2 masks manufactured at the Research Center Borstel. Lennard Meiwes, a medical student at the Universität zu Lübeck and former DZIF Academy MD scholarship holder, came up with the idea. Last year, as part of the MD scholarship, Meiwes conducted similar studies on the diagnosis of pulmonary tuberculosis in children in the Republic of Moldova. To prepare commercially available FFP2 masks with strips of polyvinyl alcohol (PVA), the group purchased a 3D printer on eBay. The printed PVA strips were then attached to the inside of the masks. These strips capture the genetic material (DNA) of tuberculosis bacteria from the air we breathe. After wearing the masks, the PVA strips were removed, dissolved, and analyzed for the presence of genetic material using the Xpert MTB/RIF Ultra rapid molecular test.
In nearly 60 percent of microbiologically confirmed cases, DNA of the tuberculosis bacterium could be detected in the mask samples. This additive benefit is particularly relevant: In six percent of patients diagnosed with pulmonary tuberculosis through the detection of the pathogen in sputum culture, molecular genetic detection of tuberculosis bacteria DNA was possible exclusively from the mask and not from the sputum. This means the procedure could provide additional diagnostic information rapidly that would not have been obtained using established methods alone.
"Our data show that face mask sampling can have relevant additional benefits in certain clinical situations: In about one in 18 people with pulmonary tuberculosis, tuberculosis bacteria could be detected in the FFP2 mask, but not in the sputum. This means that the procedure could be a useful addition to established tuberculosis diagnostics. Face mask sampling is thus one of a growing number of new, non-invasive diagnostic approaches that have the potential to improve the early identification of tuberculosis and quickly bring additional patients into therapy," comments Dr. Thomas Theo Brehm from the DZIF Clinical Tuberculosis Center (DZIF ClinTB) at the Research Center Borstel, Leibniz Lung Center, one of the last authors of the study.
Source: Press release of the Research Center Borstel, Leibniz Lung Center
