Molecular surveillance of multi- and extensively drug-resistant tuberculosis transmission in the European Union from 2003 to 2011

The European Centre for Disease Prevention and Control (ECDC) initiated a project on the molecular surveillance of multi- and extensively drug-resistant tuberculosis (MDR-/XDR-TB) transmission in the European Union (EU) in the period from 2009 to 2011. In total, 2,092 variable number of tandem repeat (VNTR) patterns of MDR-/XDR-TB Mycobacterium tuberculosis isolates were collected, originating from 24 different countries in the period 2003 to 2011. Of the collected VNTR patterns, 45% (n=941) could be assigned to one of the 79 European multiple-country molecular fingerprint clusters and 50% of those (n=470) belonged to one extremely large cluster caused by Beijing strains of one genotype. We conclude that international transmission of MDR-/XDR-TB plays an important role in the EU, especially in the eastern part, and is significantly related to the spread of one strain or clone of the Beijing genotype. Implementation of international cluster investigation in EU countries should reveal underlying factors of transmission, and show how TB control can be improved regarding case finding, contact tracing, infection control and treatment in order to prevent further spread of MDR-/XDR-TB in the EU