17 Starshinova, A.A. Sabirova, A. Sharipov, R.A. Tukfatullin, R.K. Panteleev, A.M. Nazarenko, M.M. Kudlay, D.A. contact persons Diaskintest® immunodiagnostics latent tuberculosis infection medical staff recombinant tuberculosis antigen test risk groups Scopus Web of Science Белый список 2026 2026-10-27 10.3389/fmed.2026.1835510 FRONTIERS IN MEDICINE Introduction: Identification of tuberculosis infection at different stages following exposure to a patient with tuberculosis is essential for improving epidemiological control, particularly during pathogen elimination and the stage of latent tuberculosis infection (LTBI). Detection of LTBI enables timely preventive interventions that may reduce the incidence of active tuberculosis. Healthcare workers represent an important risk group in whom LTBI screening using modern immunodiagnostic methods is required. Objective: To compare the prevalence of latent tuberculosis infection among healthcare workers in the general healthcare system, healthcare workers in tuberculosis facilities, and individuals with documented contact with patients with tuberculosis. Subjects and methods: A prospective comparative study was conducted including healthcare workers of the general healthcare system (n = 49), healthcare workers of tuberculosis institutions (n = 60), and individuals with documented contact with tuberculosis patients (n = 43). A control group consisted of healthy individuals without a history of contact with tuberculosis patients, clinical manifestations of tuberculosis, radiological signs of infection, or significant comorbidities (n = 51). Among healthcare workers in tuberculosis institutions, occupational contact with tuberculosis patients was reported in 91.7% (55/60; 95% CI 84.67– 98.66). Among contact persons, exposure to a bacteriologically confirmed tuberculosis case occurred in 76.7% (33/43; 95% CI 64.12–89.37). All participants underwent immunodiagnostic testing using a test with recombinant tuberculosis antigen (ATR). Individuals with positive ATR results underwent comprehensive examination, including computed tomography of the chest, to exclude active tuberculosis. The prevalence of LTBI was defined as the proportion of positive ATR results. Statistical analysis was performed using χ2 tests with a significance threshold of p < 0.05 using Microsoft Excel 2019. Results: Positive ATR test results were detected in 8.2% of healthcare workers in the general healthcare system (95% CI 0.50–15.83), which did not significantly differ from the control group (5.8%; 95% CI 1.41–16.54; χ2 = 0.200, p = 0.655). In contrast, positive ATR results were significantly more frequent among healthcare workers in tuberculosis institutions (23.3%; 95% CI 12.63–34.04) compared with controls (5.8%; χ2 = 6.473, p = 0.011). The highest prevalence of positive ATR results was observed among contact persons (51.2%; 95% CI 36.22–66.10), which was significantly higher than in the control group (χ2 = 24.502, p = 0.001). Comparison between risk groups demonstrated that positive ATR results were significantly more common among healthcare workers in tuberculosis institutions than among healthcare workers in the general healthcare system (23.3% vs. 8.2%; χ2 = 4.502, p = 0.034). Furthermore, contact persons showed significantly higher positivity rates than both healthcare workers in the general healthcare system (51.2% vs. 8.2%; χ2 = 20.886, p = 0.001) and healthcare workers in tuberculosis institutions (51.2% vs. 23.3%; χ2 = 8.533, p = 0.004). Conclusion: The prevalence of LTBI detected using ATR immunodiagnostics was lowest among healthcare workers in the general healthcare system (8.2%), with values comparable to those observed in the control group (5.8%). Healthcare workers in tuberculosis institutions demonstrated a significantly higher prevalence of LTBI (23.3%), reflecting increased occupational exposure. The highest prevalence was observed among contact persons (51.2%), highlighting the substantial risk associated with close exposure to tuberculosis patients and emphasizing the importance of immunodiagnostic screening for early detection of LTBI. https://repo.bashgmu.ru/publication/6188 https://repo.bashgmu.ru/files/6388