Molecular epidemiology of tuberculosis in the Czech Republic, 2004: analysis of M. tuberculosis complex isolates originating from the city of prague, south Moravia and the Moravian-Silesian region.

OBJECTIVES To compare M. tuberculosis complex genotypes from representative regions of the Czech Republic in order to estimate changes in strain prevalence and in the extent of imported drug-resistant tuberculosis. METHODS Primary M. tuberculosis complex isolates (n=155) and follow-up isolates (n=15) from 155 patients from the first half of 2004 (98 from Prague, 37 from South Moravia and 35 from the Moravian-Silesian region) were genotyped by IS6110-RFLP, spoligotyping, and partly by VNTR-genotyping. RESULTS Based on IS6110-RFLP, 110 of 155 (71%) primary isolates were unique. Forty-five isolates (29%) were found in 15 clusters comprising two to six patients and all but one cluster were also discriminated by MIRU-VNTR-genotyping. Four clusters comprised patients from different regions, and six were ongoing for several years. An indication of MDR-strain transmission was found in one instance. All four Beijing-type isolates with any resistance were associated with immigration from Eastern Europe. CONCLUSIONS The molecular epidemiological data of this period-prevalence, population based study and its comparison to earlier investigations point to a low extent of clustering between M. tuberculosis complex isolates in representative regions of the Czech Republic. Few clusters extending geographically and/or over several years were identified, providing a means for an in-depth analysis of risk factors of transmission. Beijing genotype isolates were shown to increase in prevalence to reach 6.5%. Drug resistant isolates of this genotype were associated with immigration of from Eastern Europe, although direct transmission of a resistant isolate was probable only in one of eleven cases.