The aim of the study was to evaluate the clinical features of the course of tuberculosis in infants and preschool children against herpes infection. The presence of viral infection was noted on detection of DNA viruses: the Epstein-Barr virus, herpes simplex virus type VI, cytomegalovirus in blood mononuclear cells of children. According to the results of PCR diagnosis, 28 (the 1st group) of the 61 children surveyed were infected with herpes viruses, 33 children (the 2nd group) — were not infected with those viruses. The frequency of comorbidity was higher in the 1st group. 12 of 14 children diagnosed with tuberculosis intoxication were infected with herpes viruses. Tuberculosis intoxication in the structure of the clinical forms of tuberculosis in the 1st group was 43 %, and in the 2nd group was only 6 %. The role of viral suppression of dendritic cells as a possible factor in the suppression of specific immune response to Mycobacterium tuberculosis in the mediastinal lymph nodes and the emergence of "minor" forms of tuberculosis in children was discussed.