The Korean Journal of Internal Medicine Vol. 29, No. 5 (Suppl. 1)
WCIM 2014 SEOUL KOREA 415
Slide Session
OS-021 Mycobacterial Diseases
Xpert MTB/RIF Assay for Diagnosis of Extrapulmonary Tuberculosis in a Country with an Intermediate TB Burden
Yeon Wook KIM1, Nakwon KWAK1, Moon-Woo SEONG2, Eui-Chong KIM2, Chul-Gyu YOU1, Young Whan KIM1, Sung Koo HAN1, Jae-Joon YIM1
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National Uni- versity Hospital, Korea1, Department of Laboratory Medicine, Seoul National University Hospital, Korea2 Background: The Xpert MTB/RIF assay is endorsed by the WHO for detecting pulmo- nary and extrapulmonary tuberculosis (EPTB). The aim of this study was to determine the accuracy of the Xpert MTB/RIF assay in diagnosing EPTB in South Korea, which has an intermediate TB burden.
Methods: We retrospectively reviewed the medical records of 1,426 patients in whom the Xpert MTB/RIF assay using extrapulmonary specimens was requested between January 1, 2011 and October 31, 2013 in a tertiary referral hospital in South Korea.
The sensitivity, specifi city, positive predictive value (PPV) and negative predictive value (NPV) for diagnosis of EPTB and detection of rifampicin resistance were calculated.
Results: Using culture as gold standard, sensitivity, specifi city, PPV, and NPV of the assay were 67.7%, 98.1%, 60%, and 98.6%, respectively. Higher sensitivity was shown among specimens including needle aspirates and biopsied tissues (85.7%), pus (75%), joint fl uids (100%), and urine (100%). The sensitivity, specifi city, PPV, and NPV for the detection of rifampicin resistance among specimens with positive results for M. TB were 80%, 100%, 100%, and 97.7%, respectively.
Conclusions: The Xpert MTB/RIF assay showed acceptable sensitivity and excellent specifi city for diagnosis of EPTB and detection of rifampicin resistance in a country with an intermediate TB burden.
OS-022 Mycobacterial Diseases
Drug Resistance Pattern of Mycobacterium Tuberculosis Strains from Pulmonary and Extrapulmonary
Tuberculosis in a Tertiary Medical Center in Korea, 2006-2013
Yousang Ko1, Jin Lee1, Ho Young Lee1, Young Seok Lee1, Mi-Yeong Kim1, Hyun-Kyung Lee1, Young-Min Lee1, Jeong Hwan Shin2
Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Busan Paik Hospital, Inje University College of Medicine, Korea1, Department Laboratory Medicine, Busan Paik Hos- pital, Inje University College of Medicine, Korea2
Background: The aim of this study was to evaluate the trend in the rates of drug-re- sistant tuberculosis (TB) over time, as well as the difference in the drug-resistance pattern between pulmonary TB and extrapulmonary TB at a private referral center in South Korea.
Methods: All patients with TB confi rmed by culture from 2006 to 2013 were included in this study.
Results: In total, 1745 patients were included: 1407 (80.6%) were new cases, and 338 (19.3%) were previously treated cases; 1610(92.2%) were pulmonary TB, and 135(7.7%) were extrapulmonary TB. Multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB was detected in 5.7% and 2.0% of new cases and in 20.1%
and 8.6% of previously treated cases, respectively. The trend of the analysis of change in the drug-resistance pattern in all TB cases during the study period did not show a remarkable decrease in the rate of MDR TB. In previously treated cases, the rate of MDR and XDR TB showed a signifi cant decreasing trend. MDR TB was detected to a lower extent in extrapulmonary TB compared with pulmonary TB patients.
Conclusions: The drug-resistance rate of TB, especially MDR TB, remains high at a private referral hospital, and the trend of the drug-resistance rate did not show a signifi cant decrease from 2006 to 2013. This underscores the necessity to perform a national survey regarding the prevalence of drug-resistant TB for the purpose of ob- taining the most accurate and current drug resistance status in South Korea, including the private sector.
OS-023 Mycobacterial Diseases
Clinical Signifi cance of Delayed Sputum Smear Conversion in Pulmonary Tuberculosis
Hye Seon Kang1, Ah Young Shin1, Joong Hyun Ahn1, Ju Sang Kim1 The Catholic University of Korea, Incheon St. Mary`s Hospital, Korea1
Background: Sputum culture conversion is a cardinal index in the treatment of pul- monary tuberculosis (TB). Failure to achieve sputum culture conversion after intensive anti-TB treatment is known to be a surrgate marker of treatment failure and relapse.
In spite of high accuracy, the long yield time is needed to identify sputum culture conversion. In clinical practice, sputum smears are frequently used to evaluate treat- ment response and infectivity. The purpose of this study was to evaluate concordance between two-month sputum smears and culture conversion and predicting factors of delayed sputum smears and culture conversion.
Methods: We retrospectively reviewed the medical records of all the patients diag- nosed of sputum smear positive pulmonary TB at Incheon St. Mary’s Hospital of The Catholic University of Korea between Jan 2011 and Dec 2013. Multi-drug and Exten- sively drug resistant TB were excluded. Rate and predictors of sputum conversion and culture conversion at two months were evaluated.
Results: Total 225 patients were enrolled. The sensitivity and specifi city of two-month sputum smears in predicting two-month culture conversion were 80.48% and 80.53%, respectively. Predicting factors of delayed sputum conversion were male gender (P=0.002), diabetes (P=0.006), older age (P<0.001), smoking history (P=0.005), alcohol status (P=0.02), sputum smear grade at the time of diagnosis (P=0.016), and the pres- ence of cavity (P<0.001). In evaluating culture conversion, older age (P<0.001), smok- ing history (P=0.022) and the presence of cavity (P=0.003) were factors of delayed conversion. In logistic regression analysis, the presence of cavity (P=0.040, OR=1.971) and smoking history (P=0.008, OR=2.426) were statistically signifi cant determinant of delayed sputum smear and culture conversion, respectively.
Conclusions: Sputum smears could be substitute for sputum cultures to evaluate treatment response and predict treatment outcomes. In patients having factors asso- ciated with delayed sputum smear conversion, close monitoring and vigorous treament strategy is needed.
OS-024 Mycobacterial Diseases
Evaluation the Decline in Infectiousness of Patients with Pulmonary Tuberculosis after Receiving Standard Chemotherapy Using Sputum Induction Specimen
Yousang Ko1, Young Seok Lee1, Mi-Yeong Kim1, Hyun-Kyung Lee1, Young-Min Lee1, Jeong Hwan Shin2
Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Busan Paik Hospital, Inje University College of Medicine, Korea1, Department Laboratory Medicine, Busan Paik Hos- pital, Inje University College of Medicine, Korea2
Background/Aims: It is known that the infectiousness of pulmonary tuberculosis (PTB) is determined by not smear conversion but also culture conversion since smear negative PTB patient contribute to the transmission of TB. The aim of this study was to evaluate the decline in infectiousness of patients with PTB after receiving standard chemotherapy using sputum induction specimen.
Methods: A retrospective analysis was performed on 69 PTB patients from 2013 to 2014. Among them, 21 were conducted acid fact bacilli stain and culture by induced sputum (IS) at baseline and weekly for 6 weeks. Other 49 were conduct AFB stain and culture at 4 weeks after anti-TB therapy.
Results: In total 69, 35 (50.7%) had cavitation; 29 (42.0%) were smear positive. In 40 smear negative, the positive culture rate at 4 weeks after anti-TB therapy was 15.0%
and 2.5% in liquid media (LM) and solid media (SM), respectively. In 29 smear positive, the positive culture rate was 75.9% and 13.8% in LM and SM, respectively. Of 21 per- formed SI weekly after anti-TB therapy, in 11 smear positive, the positive culture rate in LM was 100%, 90.9%, 90.9%, 72.7%, 36.4% and 18.2%, respectively. In SM culture, the positive culture rate was 100%, 55.6%, 33.3%, 11.1%, 0% and 0%, respectively.
In 10 smear negative, the positive culture rate in LM was 100%, 80%, 40%, 10%, 0%
and 0%, respectively. In SM culture, the positive culture rate was 90%, 20%, 10%, 0%, 0% and 0%, respectively.
Conclusions: The negative culture conversion in PTB after anti-TB therapy takes more times rather than conventionally expected, especially in smear positive PTB. It is need to consider the prolonged infectiousness of PTB despite no drug resistance, in TB treatment and prevention program.
