Recovery Rate of Nontuberculous Mycobacteria from Acid-Fast-Bacilli Smear-Positive Sputum Specimens.

Koh, Won Jung; Kwon, O Jung; Yu, Chang Min; Jeon, Kyeong Man; Suh, Gee Young; Chung, Man Pyo; Kim, Ho Joong; Han, Sang Won; Park, Sun Young; Lee, Nam Yong

doi:2003.54.1.22

Tuberc Respir Dis > Volume 54(1); 2003 > Article

Original Article

Tuberculosis and Respiratory Diseases 2003;54(1):22-32.
DOI: https://doi.org/10.4046/trd.2003.54.1.22 Published online January 1, 2003.

Recovery Rate of Nontuberculous Mycobacteria from Acid-Fast-Bacilli Smear-Positive Sputum Specimens.

Won Jung Koh, O Jung Kwon, Chang Min Yu, Kyeong Man Jeon, Gee Young Suh, Man Pyo Chung, Ho Joong Kim, Sang Won Han, Sun Young Park, Nam Yong Lee

¹Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. ojkwon@smc.samsung.co.kr
²Department of Laboratory Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.

Abstract

BACKGROUND
Sputum smears for acid-fast bacilli(AFB) examined microscopically is the most important diagnostic test for pulmonary tuberculosis. However, the AFB observed on the smear may represent either M. tuberculosis or nontuberculous mycobacteria(NTM). This study examined the recovery rate of NTM from the AFB smear-positive sputum specimens in a tertiary hospital in Korea. MATERIALS AND METHODS: This study analyzed the results for the 1,889 AFB smear-positive and culture-positive sputum specimens collected from 844 patients from July, 1997 to December, 2001. RESULTS: The 1,889 sputum specimens collected from 844 patients tested positive on both microscopy and culture during the 4.5 years. The NTM were recovered from 10.3%(195/1,889) of the smear-positive sputum specimens and 11.0%(93/844) of patients with smear-positive sputum. The NTM were isolated more than two times in 44.1%(41/93) of the patients from whom the NTM was recovered. Trends of the recovery rate of the NTM from the AFB smear-positive sputum specimens were increasing from 6.5%(17/262) in the latter half of 1997 to 17.8%(36/202) in the latter half of 2001 (p<0.001, test for trend). CONCLUSIONS: These results suggest that some patients with AFB smear-positive sputum have NTM pulmonary disease rather than pulmonary tuberculosis in Korea.

Key Words: Pulmonary tuberculosis, Mycobacterium tuberculosis, Atypical mycobacteria, Sputum, Microbiology, Korea