Testing for tuberculosis by analyzing the exhaled air in patients’ breath is a simpler and more effective method than analyzing their sputum.
- The World Health Organization reported 1.6 million deaths worldwide in 2021, a return to 2017 levels.
- 10.6 million people developed the disease, an increase of 4.5% compared to 2020.
- Since 2020, it has become the second leading cause of death from an infectious disease, behind Covid-19 and before AIDS.
Analyzing the air exhaled by patients proves to be a better way to screen for tuberculosis than the current gold standard of bacteriological research in sputum. These are the results of a recent pilot study published in the journal type communicationswhich make it possible to hope for a more effective diagnosis of the disease in the long term, while tuberculosis causes more than one million deaths in the world each year.
To detect tuberculosis, the classic method is not the most effective
Conducted by two teams of researchers, the first Colombian and the second French from the National Institute of Biological Sciences (INSB) of the CNRS, this research, which focused on a small group of 45 patients, revealed that this innovative approach allows to immediately diagnose the bacterium causing the disease, the bacillus Mycobacterium tuberculosis. And this, even in patients considered negative after analysis of their sputum (sputum), the traditional diagnostic technique, often used in addition to clinical examination and X-ray of the lungs.
The problem is that medical research has long identified a lack of sensitivity in this bacteriological method, especially in patients called “paucibacillary” (carriers of few bacilli in their sputum), which reduces its effectiveness. The latter include children or patients co-infected with the AIDS virus. Partly for these reasons, one in three cases is estimated to go undiagnosed.
Tuberculosis: an increase in cases for the first time in 20 years
This is why, according to the research team, it was necessary to develop other methods. Thus, they had the idea of using a relatively unknown body fluid, exhaled air condensate (the liquid phase contained in the air we exhale). In order to collect this liquid fraction, study participants first breathed into a tube whose air had been cooled so that water condensed on the walls. A simple and non-invasive gesture that does not require specialized personnel. Next, the researchers carried out a chemical and immunological analysis of this condensate of exhaled air, which revealed the presence of molecules (sugars, lipids, proteins), which the Mycobacterium tuberculosis product and which are the cause of the disease. This made it possible to distinguish “unambiguously the patients of healthy individuals or suffering from other respiratory infections”as pointed out INSB press release.
The scientists add that this method could be carried out directly at the patient’s bedside in the future, which would make it possible to screen for tuberculosis for those whose bacteriological analysis of sputum turned out to be negative. Reassuring news when for the first time in 20 years, the number of cases recorded in the world is increasing. The World Health Organization estimates that more than 10 million the number of new cases of tuberculosis per year, of which 12% are children.