Биопрепараты: Профилактика, диагностика, лечение (Sep 2019)
Diagnosis of Latent Tuberculosis Infection in Personnel of Various Institutions and Determination of the Risk Group for Tuberculosis
Abstract
Early diagnosis of tuberculosis remains essential for the prevention of the disease and control of its incidence. The diagnosis of latent tuberculosis infection (LTBI) has significantly improved over the last years due to the use of new immunological tests, including the Diaskintest.The aim of the study was to assess the potential of immunological assays for diagnosis of latent tuberculosis infection and determination of risk groups for tuberculosis among personnel of different institutions.Materials and methods: in 2015–2018, a prospective group-control study was conducted that included employees of various medical centres (n = 154) and healthy individuals (n = 30). There were no significant age differences between the subjects. All the subjects included in the study shared their medical history, underwent general examination, X-ray examination, and were tested with Diaskintest. Multispiral computed tomography (MSCT) of the chest was performed for every subject with a positive Diaskintest result.Results: the comparison of the number of persons with LTBI in general care hospitals, personnel of a manufacturing firm, and among healthy individuals showed that the risk of being infected with Mycobacterium tuberculosis is very similar in all the groups (from 6.8 to 10.0 %). The highest risk of developing LTBI was found in people who worked in an infectious area for more than 5 years (48.4 %). The analysis of the level of immune complexes (ICs) demonstrated that individuals with LTBI did not have isotypes of IgG3 and IgE immune complexes, which are found in patients with tuberculosis. The identification of particular isotypes indicates a borderline state between LTBI and tuberculosis and requires therapeutic intervention.Conclusions: the use of the Diaskintest makes it possible to distinguish groups of employees of various institutions who are at a higher risk of developing tuberculosis. At the same time, determination of the ICs helps to reveal the borderline condition which requires medical intervention.
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