Abstract
The incidence of nontuberculous mycobacteria (NTM) infection is increasing in Korea. The aim of this study was to evaluate the recovery rate of NTM from respiratory specimens over a 10-year period in a tertiary referral hospital in Korea with a intermediate tuberculosis burden.
We identified all mycobacterial isolates from respiratory specimens at the Samsung Medical Center (Seoul, Korea) obtained from January 2000 to December 2009.
During the study period, 25,374 mycobacterial isolates were recovered from 8,115 patients. The proportion of NTM isolates was continuously increasing from 31.8% (167/525) in 2000 to 68.2% (3,514/5,152) in 2009 (p<0.001, test for trend). Among the acid-fast bacilli (AFB) smear-positive specimens, recovery rate of NTM isolates was also increasing from 9.2% (18/196) in 2000 to 55.1% (1,027/1,865) in 2009 (p<0.001, test for trend). The most frequently isolated NTM organisms were Mycobacterium avium complex (n= 4,734, 52%) and Mycobacterium abscessus complex (n=2,660, 29%).
This study found a rapidly increasing trend in the isolation of NTM from respiratory specimens at a referral hospital in Korea. The high proportion of NTM even among AFB-positive respiratory specimens would represent serious challenge for the diagnosis of pulmonary tuberculosis.
- © 2012 ERS