Incidence of pulmonary tuberculosis in Korean civil servants: second study, 1992-1994

SETTING: A survey based on biennial medical examinations for civil servants , including school teachers. OBJECTIVE: To estimate the incidence of pulmonary tuberculosis (PTB) for th e general population from a sample survey, and to compare it with the previ ous results from 1988-1990. DESIGN: A retrospective follow-up study which started in April 1996 and end ed in December 1997. Development of PTB among all South Korean civil servan ts who were tuberculosis-free in the 1992 biennial medical examination was followed up to the 1994 medical examination. The survey was based on newly- developed cases by 1) the findings of the biennial medical examination, 2) scrutiny of the medical records of all those claiming health insurance for tuberculosis, and 3) checking of the TB registers in all health centres dur ing the period. Civil servants constituted 2.6% of the Korean population ag ed 20 to 64. RESULTS: Of 958 137 subjects who were found to be TB-free in the 1992 medic al examination, 957 216 were eligible for the study Radiologically active P TB was found in 4146 cases over the 2-year period of the study Bacteriologi cal examinations were performed in 3306 patients: there were 1551 bacteriol ogically proven cases (46.9%), including 1049 smear-positives (31.7%) and 5 02 smear-negative culture-positives (15.2%). The age-sex adjusted incidence rate for the general population was 202/100 000 in radiologically active P TB, 81/100 000 in bacteriologically proven PTB, and 54/100 000 in smear-pos itive PTB. Overall PTB incidence rates were higher in males (240/100 000) t han in females (163/100 000), and in the age group 20-24 years (280/100 000 ) than in the other age groups. CONCLUSION: Comparing the 1992-1994 PTB incidence with that observed in the 1988-1990 survey, the highest incidence was observed among young adults in both surveys, and it had not changed over time.