Multidrug-resistant tuberculosis over 20 years at a referral hospital in South Korea: trends and outcomes

SETTING: A referral centre in South Korea. OBJECTIVE : To investigate trends in drug resistance, treatment modalities and outcomes, and adverse events of multidrug-resistant tuberculosis (MDR-TB) over two decades. DESIGN: MDR-TB patients treated at Seoul National Hospital University between 1996 and 2015 were divided into four 5-year cohorts according to the date of initial diagnosis. Changes in demographic characteristics, drug resistance, drugs used, treatment outcomes and adverse events over time were elucidated. RESULTS: Between 1996 and 2015, 418 patients were treated for MDR-TB: 86 patients between 1996 and 2000, 125 between 2001 and 2005, 123 between 2006 and 2010, and 84 between 2011 and 2015. The proportion of patients with positive acid-fast bacilli sputum (60.5-29.7%, P < 001) or cavities on chest radiographs (86.0-40.5%, P < 001) decreased over time. Resistance to pyrazinamide, fluoroquinolones, cycloserine and p-aminosalicylic acid decreased. Later-generation fluoroquinolones (77.9-90.5%) and linezolid (0-26.2%) became more frequently prescribed. The treatment success rate increased (45.3-88.1%, P < 0.001); neurological adverse events, including peripheral neuropathy also increased (4.7-13.1%, P = 0.027). CONCLUSION: MDR-TB patients presented with less severe disease and better resistance profiles over time in South Korea, with treatment outcomes improving continuously.