Contributions of culture and antimicrobial susceptibility tests to the retreatment of patients with pulmonary tuberculosis

• Published in: Revista da Sociedade Brasileira de Medicina Tropical 2013-07, Vol.46 (4), p.441-446
• Main Authors: Andrade, Bruno Horta, Greco, Dirceu Bartolomeu, Oliveira, Maria Tereza da Costa, Lacerda, Natalia Priscila, Côrrea, Ricardo de Amorim
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Antimicrobial susceptibility testing; Antitubercular Agents - pharmacology; Antitubercular Agents - therapeutic use; Cohort Studies; Drug resistance; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Mycobacterium tuberculosis - drug effects; Pulmonary tuberculosis; Retreatment; Retrospective Studies; Treatment outcome; TROPICAL MEDICINE; Tuberculosis, Pulmonary - drug therapy; Tuberculosis, Pulmonary - microbiology; Young Adult
• ISSN: 0037-8682; 1678-9849; 1678-9849
• DOI: 10.1590/0037-8682-0047-2013

This study evaluated the efficacy of retreatment of pulmonary tuberculosis (TB) with regard to treatment outcomes and antimicrobial susceptibility testing (ST) profiles. This retrospective cohort study analyzed 144 patients treated at a referral hospital in Brazil. All of them had undergone prior treatment, were smear-positive for TB and received a standardized retreatment regimen. Fisher’s 2-tailed exact test and the χ² test were used; RRs and 95% CIs were calculated using univariate and multivariate binary logistic regression. The patients were cured in 84 (58.3%) cases. Failure was associated with relapsed treatment and abandonment (n=34). Culture tests were obtained for 103 (71.5%) cases; 70 (48.6%) had positive results. ST results were available for 67 (46.5%) cases; the prevalence of acquired resistance was 53.7%. There were no significant differences between those who achieved or not therapeutic success (p=0.988), despite being sensitive or resistant to 1 or more drugs. Rifampicin resistance was independently associated with therapeutic failure (OR: 4.4, 95% CI:1.12-17.37, p=0.034). For those cases in which cultures were unavailable, a 2nd model without this information was built. In this, return after abandonment was significantly associated with retreatment failure (OR: 3.59, 95% CI:1.17-11.06, p=0.026). In this cohort, the general resistance profile appeared to have no influence on treatment outcome, except in cases of rifampicin resistance. The form of reentry was another independent predictor of failure. The use of bacterial culture identification and ST in TB management must be re-evaluated. The recommendations for different susceptibility profiles must also be improved.