[The role of chemoprophylaxis in prevention of tuberculosis].

Chemoprophylaxis represents a preventive antituberculotic treatment of persons at singificant risk of developing tuberculosis, in whom active tuberculosis is excluded The decision on treatment is based on detailed history about close contacts, tuberculin skin testing, data on BCG vaccination, and clinical examination. Conclusions are quite different depending on the fact if BCG vaccine is routinely applied (the case in developing countries, due to high tuberculosis incidence) or not--(in developed countries, where negative tuberkulin skin test is a normal finding), and tuberculin-positive persons are considered recently infected and undergo preventive therapy. The population at increased risk of developing tuberculosis includes: close contacts of patients with acive tuberculosis, recent skin test converters or with positive purified protein derivative (PPD) test, HIV-positive persons, those with underlying diseases that increase the risk of tuberculosis (diabetes mellitus, prolonged glucocorticoid therapy, immunosuppressive therapy, terminal renalfailure, kidney transplantation, all disorders associated with malnutrition etc.), those coming from high TB prevalence countries, immigrants, alchocolics, asylants, drug addicts, patients in psychiatric hospitals, etc. Preventive therapy usually lasts for 6 months and consists of isoniazid 5mg/kg daily for adults and 10 mg/kg/daily for children.