THE 6TH NATIONWIDE TUBERCULOSIS PREVALENCE SURVEY IN KOREA, 1990

Setting: Nationwide random sample survey for tuberculosis in 1990. Objective: To investigate the prevalence of tuberculosis infection, morbidity and drug resistance and BCG coverage, and to compare the findings with those of the previous 5 surveys. Design: The following investigations were performed: tuberculin test, BCG scar screening, chest miniature radiography (70 mm x 70 mm) for those aged over 5 years, sputum direct smear, culture and drug susceptibility test, and a questionnaire to obtain history of chemotherapy and symptoms. Results: The coverage of the investigation has been of more than 95% in each survey. The main findings are as follows: BCG coverage of those aged under 30 and of infants (aged under 1 year) has increased from 24% to 86% and from 1% to 79% respectively. The observed tuberculin positivity (greater-than-or-equal-to 10 mm in diameter) of subjects aged under 30 has decreased from 45% to 27%. The reduction of positivity was significant in children aged 5-9 years, from 34% to 8%. The annual risk of infection has dropped by over 6% annually. The prevalence of pulmonary tuberculosis per 100 000 has decreased: direct smear-positive from 690-143, smear and/or culture positive from 940-241 and active cases from 5065-1842 respectively. The drug resistance rate had increased to the peak of 47% in 1980, but had decreased to 27% in the last survey. Conclusion: The tuberculosis situation has improved significantly in every aspect in the last 25 years.