[Clinical value of detection of L forms of Mycobacterium tuberculosis in patients with residual tuberculous changes in the lungs].

To clarify the role of M. tuberculosis L-form in a recurring tuberculous process in subjects with residual tuberculous changes in the lungs, microbiological, ++clinico-roentgenological and laboratory examinations of 1651 persons recorded as having VIIA, VIIB, III and 0 groups were undertaken. The causative agent of tuberculosis was isolated in a typical bacillary and L-transformed forms in 3.1 and 5.0% of the screened persons, respectively. Active respiratory tuberculosis was diagnosed in 64.7% of sputum-positive patients, including 86.3% of them as bacillary carriers and 42.7% of those excreting L-forms of the tuberculosis agent. The detection of biologically altered forms of the causative agent indicates a potential activity of the process and requires an intensified medical examination control and differential prevention activities.