Latent tuberculosis infection in the pediatric population without contact: a prospective controlled study

Background. Latent tuberculosis infection (LTBI) represents a global medical problem, affecting 25 % of the world's population with an annual registration of 1.2 million cases of tuberculosis in children under 15 years of age. Objective. To determine the features of the somatic status in children with LTBI without identified contacts with tuberculosis patients who are MbT+. Materials and methods . A prospective controlled study of 40 children (20 children with LTBI without contacts with tuberculosis patients and 20 without LTBI (control)) aged 8–17 years was conducted. Results. Children with LTBI showed a 30 % decrease in the phagocytic activity of leukocytes relative to the norm, frequent respiratory infections (89 %), and multiple comorbid disorders: grade 2 obesity (50 % versus 10 % in the control), connective tissue dysplasia (40 % versus 10 %), allergic diseases (60 %), dental caries and aphthous stomatitis (34 % versus 8.5 %). High titers of antibodies to Giardia (3.2 times higher than control) contribute to the suppression of the immune response, creating conditions for the persistence of M. tuberculosis. Primary tuberculosis infection in children with LTBI occurred before the age of 3 years in 60 % of cases, whereas in the control group, it occurred only in 10 %. Despite long-term anti-tuberculosis chemotherapy, a positive reaction to the Diaskin test persisted in 90 % of children with LTBI, which is associated with the formation of resident memory T-cells. Conclusions . Children with LTBI without contacts represent a group with a unique immuno-metabolic profile requiring a personalized approach, an expanded vaccination schedule, and interdisciplinary follow-up for at least 5 years to reduce the risks of developing active tuberculosis and correct comorbid conditions.