BACKGROUND/AIMS: We evaluated the trend in the rates of drug-resistant tuberculosis (TB) over time, as well as the difference in the drug-resistance pattern between pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) at a private referral center in South Korea. METHODS: All patients with culture-confirmed TB from 2006 to 2013 were included. RESULTS: In total, 1,745 patients were included: 1,431 (82.0%) were new cases, and 314 (18.0%) were cases treated previously; 1,610 (92.3%) were diagnosed with PTB, and 135 (7.7%) were diagnosed with EPTB. Multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB were detected in 5.8% and 2.0% of new cases and in 20.1% and 8.6% of previously treated cases, respectively. The MDR TB rate during the study period decreased remarkably, whereas the MDR and XDR TB rates decreased significantly in previously treated cases. No difference in the drug-resistance rate was detected between PTB and EPTB. CONCLUSIONS: The TB drug-resistance rate, particularly that of MDR TB, remained high at a private referral hospital, and the drug-resistance rate did not decrease significantly from 2006 to 2013. This finding underscores the need for a national survey regarding the prevalence of drug-resistant TB to obtain the most accurate and current drug-resistance status in South Korea, including the private sector.
Adult ; Aged ; Antitubercular Agents/*therapeutic use ; *Drug Resistance, Multiple, Bacterial ; Extensively Drug-Resistant Tuberculosis/drug therapy/microbiology ; Female ; Hospitals, Private ; Humans ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Mycobacterium tuberculosis/*drug effects/isolation & purification ; Prevalence ; Republic of Korea/epidemiology ; Retrospective Studies ; *Tertiary Care Centers ; Time Factors ; Treatment Outcome ; Tuberculosis, Multidrug-Resistant/diagnosis/*drug therapy/epidemiology/*microbiology ; Tuberculosis, Pulmonary/diagnosis/*drug therapy/epidemiology/*microbiology

The diagnostic accuracy of the data reported in the Korean tuberculosis surveillance system (KTBS) has not been adequately investigated. We reviewed the clinical data of pulmonary tuberculosis (PTB) cases notified from private medical facilities through KTBS between January and June, 2004. PTB cases were classified into definite (culture-proven), probable (based on smear, polymerase chain reaction, histology, bronchoscopic finding, computed tomography, or both chest radiograph and symptoms) or possible (based only on chest radiograph) tuberculosis. Of the 1126 PTB cases, sputum AFB smear and culture were requested in 79% and 51% of the cases, respectively. Positive results of sputum smear and culture were obtained in 43% and 29% of all the patients, respectively. A total of 73.2% of the notified PTB cases could be classified as definite or probable and 81.7% as definite, probable, or possible. However, where infection was not confirmed bacteriologically or histologically, only 60.1% of the patients were definite, probable, or possible cases. More than 70% of PTB notified from private sectors in Korea can be regarded as real TB. The results may also suggest the possibility of over-estimation of TB burden in the use of the notification-based TB data.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Female ; Humans ; Male ; Middle Aged ; Mycobacterium tuberculosis/isolation & purification ; Private Sector ; Republic of Korea/epidemiology ; Severity of Illness Index ; Sputum/microbiology ; Tuberculosis, Pulmonary/*diagnosis/epidemiology/pathology ; Young Adult

Although it is not rare to find sputum that is positive acid-fast bacilli (AFB) smear but subsequent culture fails to isolate mycobacteria in clinical practice, the incidence and clinical implication of those sputa from new patients has not been clearly elucidated. The aim of this study was to determine the incidence and clinical implication of sputum with positive AFB smear but negative in mycobacterial culture. All sputa that were positive AFB smear requested during diagnostic work up for new patients visiting Seoul National University Hospital from 1 January 2005 through 31 December 2006 were included. Sputa producing a positive AFB smear but negative mycobacterial culture were classified into one of four categories: laboratory failure to isolate mycobacteria, false positive AFB smear, pathogen may show a positive AFB smear other than mycobacteria, and indeterminate results. Out of 447 sputa with a positive AFB smear, 29 (6.5%) failed to culture any organism. Among these 29 sputa, 18 were caused by laboratory failure to isolate mycobacteria, six were false positive smears, and five indeterminate. Although most sputum with a positive AFB smear but negative culture could be classified as a laboratory failure, clinicians should consider the possibility of false positive AFB smear.
Adult ; Aged ; Aged, 80 and over ; Bacterial Typing Techniques ; Bacteriological Techniques ; False Positive Reactions ; Female ; Humans ; Incidence ; Korea ; Male ; Middle Aged ; Mycobacterium/*metabolism ; Retrospective Studies ; Sputum/*microbiology ; Tuberculosis, Pulmonary/diagnosis/epidemiology/microbiology

BACKGROUND/AIMS: Although indoor air pollution is a well-known risk factor for tuberculosis (TB), the possible link between outdoor air pollution and TB development has not been examined fully. We assessed the impact of outdoor air pollution on TB development in the Seoul metropolitan area, South Korea. METHODS: The mean concentrations of ambient particulate matter (PM) with an aerodynamic diameter < or = 10 microm (PM10), O3, CO, NO2, and SO2 levels in Seoul, between January 1, 1997 and December 31, 2006, were determined. Furthermore, their association with the risk of developing TB after adjusting for socioeconomic status, between January 1, 2002 and December 31, 2006, was investigated. RESULTS: Between January 1, 2002 and December 31, 2006, a total of 41,185 TB cases were reported in Seoul. Concentrations of PM10, O3, CO, and NO2 were not associated with TB incidence in males or females. However, the interquartile increase in SO2 concentration was associated with a 7% increment in TB incidence (relative risk [RR], 1.07; 95% credible interval [CrI], 1.03 to 1.12) in males but not in females (RR, 1.02; 95% CrI, 0.98 to 1.07). CONCLUSIONS: Long-term exposure to ambient SO2 increased the risk of TB in males.
Adult ; Aged ; Air Pollution, Indoor/*adverse effects ; Female ; Humans ; Incidence ; Inhalation Exposure/adverse effects ; Male ; Middle Aged ; Odds Ratio ; Particle Size ; Particulate Matter/adverse effects ; Republic of Korea/epidemiology ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Sex Factors ; Sulfur Dioxide/*adverse effects ; Time Factors ; Tuberculosis, Pulmonary/diagnosis/*epidemiology/microbiology ; *Urban Health