Essentials of tuberculosis control for the practising physician. Tuberculosis Committee, Canadian Thoracic Society

Abstract

OBJECTIVE: To recommend guidelines for the management of tuberculosis (TB), particularly in high-risk groups including poor and homeless people, aboriginal Canadians, immigrants from countries where TB is highly prevalent and people with HIV infection. OPTIONS: Diagnosis, pharmacotherapy, vaccination and chemoprophylaxis. OUTCOMES: Prevention of infection and diagnosis and cure of TB. EVIDENCE: The evidence was gathered in late 1992 from previous guidelines, recommendations by specialist societies and new studies. VALUES: Evidence was categorized into four levels: I, randomized clinical trials of therapeutic interventions or prospective studies of diagnostic strategies; II, case-control studies; III, retrospective descriptive studies; and IV, consensus of the committee members and published statements. The Tuberculosis Committee of the Canadian Thoracic Society comprises experts in TB from across Canada. BENEFITS, HARM AND COSTS: The benefits of early diagnosis and prompt initiation of therapy are well documented. The cost effectiveness of antituberculous therapy in developing countries is well documented. In developed countries chemoprophylaxis has been shown to be cost effective, and directly observed chemotherapy has recently been hypothesized to have economic benefits. RECOMMENDATIONS: In the appropriate clinical setting, particularly when patients are known to be at high risk of TB, clinicians should consider TB, reserve body secretions for mycobacteriologic tests and conduct other investigations such as chest radiography. Furthermore, if TB is strongly suspected or confirmed by appropriate investigation the early initiation of multi-drug therapy, including at least three first-line drugs, is strongly recommended. If drug resistance is suspected a regimen of four to five drugs, including at least two drugs with which the patient has not been treated, should be started. If the strain is found to be resistant to any of the drugs in the regimen appropriate changes should be made. Chemoprophylaxis should be considered especially in contacts with a recent significant reaction to the purified protein derivative (PPD) skin test and in people known to be at risk of reactivated TB infection, particularly those with HIV infection and a significant PPD skin-test result. Vaccination with bacillus Calmette-Guerin should be limited to high-risk groups, particularly aboriginal Canadians living on reserves. VALIDATION: These recommendations are based on a consensus of Canadian experts supported by other specialist societies and reference groups. They have been reviewed by the Standards Committee of the Canadian Thoracic Society. SPONSOR: The Canadian Lung Association and the Tuberculosis Committee of the Canadian Thoracic Society.