Jung-Yien Chien1, Yi-Ting Chen2, Chin-Chung Shu3, Jen-Jyh Lee4, Jann-Yuan Wang5, Chong-Jen Yu3, Pan-Chyr Yang3. 1. Chest Hospital, Department of Health, Executive Yuan, Tainan; Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan. 2. Department of Internal Medicine, Buddhist Tzu Chi General Hospital, Hualien, Taiwan. 3. Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan. 4. Department of Internal Medicine, Buddhist Tzu Chi General Hospital, Hualien, Taiwan; Department of Internal Medicine, School of Medicine, Tzu Chi University, Hualien, Taiwan. 5. Chest Hospital, Department of Health, Executive Yuan, Tainan. Electronic address: jywang@ntu.edu.tw.
Abstract
BACKGROUND: Sputum samples from patients with non-multidrug-resistant (non-MDR) pulmonary TB may remain smear-positive for acid-fast bacilli (AFB) at the fifth month of anti-TB treatment. However, its significance remains unknown. METHODS: From January 2004 to April 2009, there were 5,403 patients with culture-confirmed pulmonary TB from four hospitals in Taiwan. Among them, 116 patients (2.2%) with non-MDR TB whose sputum samples were smear-positive by concentration smear method at the fifth month of treatment were evaluated. RESULTS: Sputum culture yielded Mycobacterium tuberculosis in 10 patients (8.6%, MTB group), nontuberculous mycobacteria in 23 (19.8%, NTM group), and no growth in the remaining 83 (71.6%, no-growth group). The relapse rate (22%) was higher in the MTB group (P = .01). Four predictors, smear grading ≥ 3+ at the fifth month ("S") (OR, 10.73; 95% CI, 2.67-43.17), no sputum culture conversion on the second month ("C") (OR, 7.16; 95% CI, 1.45-35.44), lack of directly observed therapy ("O") (OR, 6.40; 95% CI, 1.54-26.56), and no radiographic improvement at the fifth month ("R") (OR, 4.18; 95% CI, 1.02-17.10), were associated with viable M tuberculosis (MTB group). An integrated "SCOR" index of 1 point for each positive factor had the best discriminatory power for predicting culture results at the fifth month. If the SCOR index was 0, all smear-positive sputum was culture-negative for M tuberculosis. CONCLUSIONS: Positive sputum smears by a concentrated smear method at the fifth month of treatment in patients with non-MDR TB, especially those with a low SCOR index, may be due to nonviable bacilli and NTM. Careful review of the quality of patient supervision, bacteriologic data, and chest radiography is crucial.
BACKGROUND: Sputum samples from patients with non-multidrug-resistant (non-MDR) pulmonary TB may remain smear-positive for acid-fast bacilli (AFB) at the fifth month of anti-TB treatment. However, its significance remains unknown. METHODS: From January 2004 to April 2009, there were 5,403 patients with culture-confirmed pulmonary TB from four hospitals in Taiwan. Among them, 116 patients (2.2%) with non-MDR TB whose sputum samples were smear-positive by concentration smear method at the fifth month of treatment were evaluated. RESULTS: Sputum culture yielded Mycobacterium tuberculosis in 10 patients (8.6%, MTB group), nontuberculous mycobacteria in 23 (19.8%, NTM group), and no growth in the remaining 83 (71.6%, no-growth group). The relapse rate (22%) was higher in the MTB group (P = .01). Four predictors, smear grading ≥ 3+ at the fifth month ("S") (OR, 10.73; 95% CI, 2.67-43.17), no sputum culture conversion on the second month ("C") (OR, 7.16; 95% CI, 1.45-35.44), lack of directly observed therapy ("O") (OR, 6.40; 95% CI, 1.54-26.56), and no radiographic improvement at the fifth month ("R") (OR, 4.18; 95% CI, 1.02-17.10), were associated with viable M tuberculosis (MTB group). An integrated "SCOR" index of 1 point for each positive factor had the best discriminatory power for predicting culture results at the fifth month. If the SCOR index was 0, all smear-positive sputum was culture-negative for M tuberculosis. CONCLUSIONS: Positive sputum smears by a concentrated smear method at the fifth month of treatment in patients with non-MDR TB, especially those with a low SCOR index, may be due to nonviable bacilli and NTM. Careful review of the quality of patient supervision, bacteriologic data, and chest radiography is crucial.
Authors: Tumaini J Nagu; Donna Spiegelman; Ellen Hertzmark; Said Aboud; Julie Makani; Mecky I Matee; Wafaie Fawzi; Ferdinand Mugusi Journal: PLoS One Date: 2014-03-18 Impact factor: 3.240