Drug resistance among Mycobacterium tuberculosis strains in immigrants: is there a real threat everywhere?

A study was performed to determine the impact of drug resistance in tuberculosis among immigrant patients in Madrid, Spain. During the period 1995-2001, the relative proportion of isolates from immigrant patients increased from 4.4% to 24.2%. No differences between immigrants and Spanish-born patients were detected for resistance to any first-line anti-tuberculous drug. More studies are required to determine the actual incidence of resistant tuberculosis in immigrants.