Abstract: Objective To reveal the epidemiology characteristic and the risk factors in the relapse tuberculosis cases after received short-course chemotherapy. Method To follow-up the cured cases in tuberculosis control project supported by Henan provincial government and to identify the relapse cases within three years. Results The relapse rate with sputum positive tuberculosis in Henan tuberculosis control project was 3.12%, and the relapse rate in cases whose sputum smear converted negative in two months, three months and over three months with chemotherapy were 2.13%, 4.23% and 8.85% respectively (P＜0.01). There was no significant difference among the cases with the quantity eliminated sputum tubercle bacillus. Conclusion It was a risk factor to recur that the time converted negative for tubercle bacillus in sputum of tuberculosis with chemotherapy. The longer time converted sputum smear negative, the higher relapsed rate. But there was no significant difference between male and female. There was no effect-reaction relationship in tubercular bacillus quantity eliminated by tuberculosis case in sputum. It was reasonable and feasible that the cases were followed up for one year after cured with finishing full course chemotherapy . The poverty and elder TB patients with cavity was high risk population to relapse, so it must be stressed to follow up them.

Key words: Tuberculosis/epidemiology, Relapse, Follow up, Influence factors