Epidemiologic Characteristics of Extrapulmonary Tuberculosis in Korea, 1995-2010: Microbiological Diagnosis versus Clinical Diagnosis

Background: The aim of the present study was to investigate the epidemiologic characteristics of extrapulmonary tuberculosis (EPTB) in Korea. In addition, the results of culture-confirmed (CC) EPTB were compared with those of clinically-diagnosed (CD) EPTB. Methods: We retrospectively reviewed non-duplicate data of tuberculosis from the Samsung Medical Center from 1995 to 2010. A total of 6,249 and 38,726 cases of tuberculosis were CC and CD EPTB cases, respectively. The cases were categorized according to the type of specimen or by the clinicallyaffected sites. Results: The proportions of EPTB among all tuberculosis cases were 12% (745/6,249) and 22% (8,608/ 38,726) of the CC and CD cases, respectively. The distribution of both age and gender between pulmonary tuberculosis (PTB) and EPTB cases were significantly different (P＜0.001). The most common types of EPTB were tuberculous lymphadenitis, pleural TB, and abdominal TB. Pleural involvement was more common in males, while lymph node involvement was observed more frequently in females in both the CC and CD cases (M/F ratio in regards to pleura were 1.63 and 2.08, while M/F ratio in regards to the lymph node were 0.46 and 0.54). Conclusion: The dataset of EPTB cases in Korea was first evaluated over a 16-year period and compared the cases of CC EPTB to those of CD EPTB. The epidemiologic characteristics of EPTB were different from that of PTB as well as the EPTB of other countries. The present study might provide useful information regarding the epidemiology of EPTB in Korea and other countries. (Korean J Clin Microbiol 2012;15:92-97)