Bacteriological indicators in estimating therapy efficiency for newly diagnosed pulmonary tuberculosis

Abstract

Objectives - to evaluate the main bacteriological indicators for newly diagnosed pulmonary tuberculosis and to compare them with the timing of sputum smear negative reaction and abacillation. Materials and methods. The study included 127 people with newly diagnosed pulmonary tuberculosis. Bacteriological and radiological data were evaluated at 2, 4 and 6 months of the study. The patients were divided into 2 groups: patients with an ineffective course of chemotherapy (1st group, n = 67) and an effective chemotherapy (2d group, n = 60). Results. In the 1 st group, the patients with the following processes prevailed over the 2nd group: destructive (86.4% vs 40.0%; р < 0.001), generalized (76.1% vs 50.0%; р = 0.003), bilateral (62.7% vs 36.7%; р = 0.004), with bacterial excretion (68.7% vs 33.3%; р < 0.001). The difference in mass of bacterial excretion in the compared groups was insignificant (p > 0.050). The Mtb growth in solid medium was absent within 90 days in patients with effective chemotherapy (28.3% vs 1.5% in the 1 st group, р < 0.001). The low intensity of Mtb growth was also observed in the 2nd group (46.5% vs 21.2%; р = 0.006). XDR of Mtb was registered in 16.4% of patients in the 1st group, versus 5% in the 2nd group (p = 0.04). In the 1st group, the sputum smear microscopy was revealing bacteria discharge in 29.8% of patients during 12 months. In the 2nd group, the abacillation was registered in all the patients after 6 months of treatment. During the 6-8 months of chemotherapy, the abacillation was registered in 41.9% of patients in the 2nd group, and in 13.6% of patients in the 1st group (р = 0.020). After 12 months of treatment, the Mtb growth in solid medium was present in 57.6% of patients in the 1st group, compared to the 20.9% in the 2nd group (p < 0.001). Conclusion. The results of our study indicate the relationship of Mtb drug resistance, XDR in particular, and the rate of Mtb division to the generalization of the process, the tendency for destruction of lung tissue, as well as the early appearance of bacterial excretion and, accordingly, the longer periods for sputum negative reaction and abacillation.