[Epidemiologic study of the risk of tuberculosis recurrence in the Bas-Rhin, 1967-77]

The authors report an "analytic epidemiological" study, showing the risk of relapse in tuberculous patients in the Bas-Rhin in 1967 to 1977. This was possible thanks to statutory notification of tuberculous cases, with an index updated by annual returns. The study relates to French subjects notified as new cases of all forms of active tuberculosis between 1967 to 1975, going out the active file on or before 31.12.1976, and followed until 31.12.1977 after the cessation of chemotherapy. Amongst those gone out the active list, 5% were lost to follow up, 15% died, and 80% were alive (and bacteriologically inactive) at the end of treatment. In this latter group cases of relapse were observed between 1969 and 1977. Thus, 3,327 patients were at risk a relapse during the first year, and when the study was completed after 8 years, 76 relapses were observed. Two methods were used to calculate the risk of relapse. The first reported the number of relapses (76) to the number of people-years (14,500 for the 3,327 patients). The mean annual risk was 5,24%. The role of certain risk factors for a relapse could be identified more precisely: Sex, 5,43% in men and 3,19% in women, Age, 4,76% before 55, 8.36% after, Initial bacteriology 5,9% for positive cases and 3,27% for negative cases. Use of Rifampicin, 3,9% for users, 5,8% for non-users. The second calculation was based on actuarial method, giving the annual and cumulative risk as a function of the exposed population each year, for the period of the study.(ABSTRACT TRUNCATED AT 250 WORDS)