Chemoprophylaxis of tuberculosis

Abstract

With the decline of new cases of tuberculosis, and the fact that the majority of these cases arise in those previously infected, the question of who should receive preventive therapy is still not completely clear. The fact that INH has significant and at times fatal side effects makes it unclear whether the ultimate danger to the patient is the disease or its treatment. It seems that people at especially high risk, including those with abnormal chest x-rays and positive PPDs and close contacts at high risk should be treated for six to twelve months with preventive therapy depending on their risk for developing INH induced hepatitis. Adolescents and children with positive skin tests can be treated with preventive therapy due to their low risk of adverse effects from INH. Physician and patient should make an informed treatment decision based on the implication of and treatment needed for an active case of tuberculosis today, and the relative risk of INH-induced hepatic injury. Individual risk/benefit decisions must be made before recommending blanket prophylaxis for certain groups. With the recent success of intermittent and short term chemotherapeutic regimes, the entire question of chemoprophylaxis needs to be reexamined. Current pulmonology might even suggest using SGOT's measured monthly during the first four months, as this appears to provide 90% efficacy. New studies are needed that will indicate present rates of conversion, tuberculin reactivity, and incidence of disease, and that will detail not only the most effective regimen of preventive therapy, but toward whom it should be directed.