Standardised PCR-based molecular

ABSTRACT: A population-based molecular epidemiology investigation has been undertaken to evaluate tuberculosis transmission and control in the Brussels-Capital Region (Belgium). All tuberculosis cases reported from January 2003 to December 2004 were investigated. In total, 536 Mycobacterium tuberculosis isolates (89 % of culture-positive samples) were genotyped by the newly standardised 24 loci-based mycobacterial interspersed repetitive unit-variable number tandem-repeat typing, spoligotyping and IS6110 fingerprinting. Of all the patients, 30 % were grouped based on strain clusters, suggesting a transmission index of 20%. An unsuspected outbreak entailing o23 patients was evidenced by molecular typing analysis and confirmed by contact tracing. Foreign-born status accounted for 79 % of the studied patients, including 37.9 % illegal immigrants and asylum seekers. Among foreign-born patients, asylum seekers and illegal immigrants were significantly less abundant in strain clusters than settled residents. Tuberculosis in the Brussels-Capital Region is a bi-faceted problem, comprising both persisting recent transmission and ‘‘imported diseases’’. Molecular epidemiology based on real-time genotyping techniques has proven invaluable in better understanding tuberculosis transmission. However, it will most efficiently contribute to tuberculosis control when implemented in an integrated public health system