Level of Mycobacteria in Pre-Treatment Sputum and Susceptibility of M. tuberculosis Strains Isolated from Patients with non-Multidrug-Resistant Pulmonary Tuberculosis AFB (+) and Factors Influencing MGIT Results after the First 8 Weeks of Anti-Tuberculosi
Authors: Dong Pham Dinh , Cuong Nguyen Kim , Thi Phuong Nguyen , Ngoc Hong Nguyen , Van Hung Nguyen , Son Nhat Bui , Thi Luyen Le 
Published: March 2021

Vietnam is among 30 high TB ​​burden countries even though the Vietnam National TB Program has made great efforts to detect and treat tuberculosis. Objectives: Assessment of Mycobacterial level in sputum before treatment, and susceptibility to the first line anti-TB drugs of M. tuberculosis strains isolated from TB patients with AFB (+) and non-multidrug-resistant. Moreover, factors influencing MGIT outcome after the first 8 weeks of first-line anti-TB drugs therapy in patients with pulmonary tuberculosis was also analysed. Methodology: An observational, analytical study was performed in 128 patients with non-multidrug-resistant pulmonary tuberculosis AFB (+) for evaluating the level of Mycobacteria in sputum before treatment by smear microscopy method; the susceptibility of M. tuberculosis isolated from sputum of the patient was analysed by Lowenstein - Jensen method. Factors affecting positive MGIT results after 2 months of treatment were determined by multivariate logistics regression. Results: The patients had AFB 3+ were 28% in new cases and 24,5% retreatment patients. The rate of M. tuberculosis strains was susceptible to the first line anti-TB drugs in new cases was higher than retreatment patients. The percentage of any anti-TB drug resistance in retreatment tuberculosis was 59,6%, higher than that of new case TB (23,6%). There was high rate of M. tuberculosis strains resistant to Streptomycin and Isoniazid (12,5% and 16,8% for new cases; 42,3% and 36,5% for retreatment cases, respectively). Large radiographic chest lesions and high AFB levels in pre-treatment sputum were factors associated with a positive MGIT result after the first 8 weeks of treatment. Conclusion: Most of TB patients had high level of Mycobacteria in sputum samples collected before treatment. The percentage of M. tuberculosis strains isolated from sputum of pulmonary non MDR-TB patients had any anti-TB drug resistance were high. High Mycobacteria level in pre-treatment sputum and radiographic chest lesions related to positive MGIT result after the first 8 weeks of treatment.

Keywords

Pulmonary tuberculosis, first-line anti-TB drugs, anti-TB drug resistance, susceptibility, M. tuberculosis.

References

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