Two-year follow-up of directly-observed intermittent regimens for smear-positive pulmonary tuberculosis in China

SETTING: The tuberculosis component of the Infectious and Endemic Disease Control Project in the People's Republic of China is the largest single tuberculosis control project in the world using directly-observed therapy and standardized intermittent regimens. OBJECTIVE: To determine the two-year relapse and mortality rates following completion of treatment. DESIGN: A prospective cohort study of 649 cases cured in this project. The 306 new and 343 retreatment cases were treated under field conditions with 2H3R3Z3S3/4H3R3 and 2H3R3Z3E3S3/6H3R3E3, respectively. Following treatment completion, two sputum samples were collected every six months for two years and examined for acid-fast bacilli. Causes of death were identified. RESULTS: The two-year relapse rates for new and retreatment cases were 3.3% and 5.6%, respectively. Retreatment cases with delayed sputum conversion had a greater risk for subsequent relapse. The two-year mortality rate for new and retreatment cases was 3.3% and 8.5%, respectively. The higher mortality rate in retreatment cases was not attributable to relapse of disease, but rather to non-infectious sequelae of tuberculosis. CONCLUSION: The use of directly-observed intermittent regimens is effective in permanently removing infectious tuberculosis cases from the community.