Standardised PCR-based molecular epidemiology of tuberculosis.
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 > or = 23 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.
Allix-Béguec
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Laboratoire Tuberculose et Mycobactéries, Institut Pasteur, Bruxelles (Institut Scientifique de Santé Publique), rue Engeland 642, 1180 Bruxelles, Belgium.
Supply
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Wanlin
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Bifani
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Fauville-Dufaux
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D000293:Adolescent; D000328:Adult; D001530:Belgium / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D016358:Contact Tracing; D003430:Cross-Sectional Studies; D016172:DNA Fingerprinting; D054242:Emigrants and Immigrants; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats / Q000235:genetics; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D014376:Tuberculosis / Q000453:epidemiology* / Q000235:genetics* / Q000635:transmission