The spread of drug-resistant strains of Mycobacterium tuberculosis poses a significant threat to the health of medical personnel and the patients themselves. Traditionally, it is believed that wearing light medical masks by TB patients reduces the spread of mycobacteria. However, this statement has not yet been studied in detail.

Despite the fact that this event is included in official clinical recommendations, no real evidence has yet been received of its effectiveness, and it should therefore be noted the great importance of obtaining evidence of the effectiveness of the wearing of medical masks for patients with pulmonary tuberculosis.

Researchers led by Dr. Ashwin Dharmadhikari (Brighamand Women's Hospital in Boston) quantitatively evaluated the effectiveness of wearing medical masks for patients with multidrug-resistant strains of mycobacterium tuberculosis.

For 3 months, 17 patients with pulmonary tuberculosis caused by strains of multidrug-resistant mycobacteria were treated in a specialized service and wore medical masks every two days. The air in the room entered two identical rooms, each housing 90 guinea piglets not infected with Mycobacterium tuberculosis, which breathed the air of the room when the patients wore masks (main group, n = 90) and if the patients were in the room without mask (group control; n = 90). The effectiveness of wearing masks was judged by the differences in infection between the pigs in the main and control groups.

69 piglets in the control group (76.6%, 95% CI 68-85%) and 36 in the main group (40%, 95% CI 31-51%) were infected with mycobacterium tuberculosis. The reduction in the risk of spread of mycobacterium tuberculosis when patients wore masks was 56% (95% CI 33-70.5%). Based on the results of the study, in some regions where the prevalence of tuberculosis is high (for example in South Africa), simple measures can be used to reduce the spread of the infection. However, since masks are not able to completely eliminate the infection, it is obviously impossible to rely only on wearing masks.

Thus, medical masks considerably reduce the risk of transmission of mycobacteria and thus represent an additional means of preventing the spread of tuberculosis from infected patients to healthy people.