Screening and treatment of immigrants and refugees to Canada for tuberculosis: Implications of the experience of Canada and other industrialized countries.

OBJECTIVE: To assess the incidence of tuberculosis in immigrants and refugees in Canada and other industrialized countries; the effectiveness of the screening process; the incidence of drug resistance; recommendations for prophylaxis and therapy; and indications for and effectiveness of directly observed therapy. DATA SOURCES: medline search of literature published from 1985 to 1995 with the key words 'tuberculosis', 'Canada', 'screening', 'drug resistance', 'drug resistance, multiple', 'immigration and emigration', and the title words 'directly observed therapy'. STUDY SELECTION: All studies reporting data on incidence, the outcomes of screening, drug resistance, therapy and directly observed therapy were selected. DATA SYNTHESIS AND
CONCLUSIONS: Data synthesis led to the conclusions that immigrants and refugees to Canada have five times the nonimmigrant and non-Aboriginal rate of tuberculosis; that screening programs discover new cases of tuberculosis on and after arrival and that up to 20% of those scheduled to attend a tuberculosis clinic after arrival may never attend; that drug resistance is widespread in countries from which Canada receives immigrants; and that directly observed therapy for active cases can result in 100% conversion rates.