The Prospective Use of BGC and Isoniazid Chemoprophylaxis in Prevention of Tuberculosis in Developed and Developing Countries

¹ Clinica Tisiologia della Universitá di Roma Centro Studi "C. Forlanini" dell'I.N.P.S.

The author outlines the manifold problems connected with the relationship between the BCG vaccine and the isoniazid chemoprophylaxis, and reaffirms, in the first place, the fundamental views emerging from the experience gained all over the world, and, in particular, from the studies carried out at the C. Forlanini Institute, in Rome.

Chemoprophylaxis is not antithetic to vaccination, because the former is essentially carried out on tuberculin-positive subjects, whereas the latter is given on tuberculin-negative subjects. Chemoprophylaxis does not interfere with the immunity afforded by vaccination, provided it is not given simultaneously to the same subject; it is well tolerated in the great majority of cases. It does not give rise to isoniazid-resistance phenomena; during the period isoniazid is administered, it is capable of affording patients, at least on 80 per cent of cases, a protection against complications and early dissemination of tuberculosis.

In those countries where control of tuberculosis has already reached high stage of efficiency, chemoprophylaxis is very important (especially in the countries where the BCG vaccine is not systematically employed). It should be scheduled, in a selective way, for subjects living with infected individuals; on tuberculin-positive children under five years of age; for adolescents and adults with a recent positive tuberculin test; on miners with silicosis; on tuberculin-positive subjects hospitalized in mental institutions and subjects with inactive tuberculous foci.

In developing countries with a high tuberculosis incidence, the fundamental method of specific prophylaxis consists in the vaccination with BCG; but even in such countries, chemoprophylaxis may prove helpful, in conjunction with home and hospital chemotherapy, especially when it is carried out in the so-called "resevoirs" of tuberculosis infected family groups and communities.