Tuberc Respir Dis.  2003 Jan;54(1):22-32. 10.4046/trd.2003.54.1.22.

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

• Koh WJ
• Kwon OJ
• Yu CM
• Jeon KM
• Suh GY
• Chung MP
• Kim HJ
• Han SW
• Park SY
• Lee NY

• KMID: 1883780
• DOI: http://doi.org/10.4046/trd.2003.54.1.22

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.

Keyword

Pulmonary tuberculosis; Mycobacterium tuberculosis; Atypical mycobacteria; Sputum; Microbiology; Korea

MeSH Terms

Diagnostic Tests, Routine
Humans
Korea
Lung Diseases
Microscopy
Mycobacterium tuberculosis
Nontuberculous Mycobacteria*
Sputum*
Tertiary Care Centers
Tuberculosis
Tuberculosis, Pulmonary