Isoniazid Chemoprophylaxis of Latent Primary Tuberculosis: in Five Trial Centres in France from 1959 to 1969

Abstract

The object of this study is to assess the effect of chemoprophylaxis applied as quickly as possible after the date of tuberculin conversion on the risk of post-primary morbidity. 2,970 subjects aged 5 to 24 years were recruited and randomly allocated to 2 groups, one receiving isoniazid for a duration of at least 5 months, the other constituting the control group. These cases were included in this prospective and longitudinal survey from 1959 to 1966. Surveillance was carried on till 1969. Thus the duration of the observation varies from 3 to 10 years. From statistical analysis carried out according to the actuarial method, the risk of tuberculous morbidity is found to be 3 times lower in those submitted to chemoprophylaxis (0,9 g per cent) than In those who did not take the drug (2.72 per cent). This study was preceded by a survey involving 5,000 cases including a majority of latent tuberculosis in subjects under 25 years. The effective action of antibacillary drugs was shown previously.