DNA fingerprinting as an indicator of active transmission of multidrug-resistant tuberculosis in Poland

AbstractObjectives: To use genetic fingerprinting to investigate the epidemiology of tuberculosis (FB) caused by Mycobacterium tuberculosis in Poland, a country with a relatively high incidence of tuberculosis, to improve TB control.Design: One hundred M. tuberculosis isolates from 98 patients in the Institute of Tuberculosis and Lung Diseases in Warsaw from 1993 to 1995 and 85 isolates obtained from 50 patients in the Hospital of Lung Diseases in Lodz in 1996 were subjected to DNA restriction fragment length polymorphism (RFLP) analysis, using the insertion sequence IS6110 as a probe.Results: IS6110-associated banding patterns of the M. tuberculosis isolates originating from different localities varied considerably, but isolates from Lodz had a higher degree of similarity. Strains with identical RFLP types were identified in patients of the same family or patients living in the same area, indicating active transmission. Of strains isolated in Warsaw, 45% were resistant to at least one drug, and 35% were resistant to two or more drugs and were classified as multidrugresistant ( MDR). Some drug-resistant isolates were found to have identical banding patterns and originated from epidemiologically linked cases.Conclusions: Active transmission of TB, including MDR TB, is occurring in Poland. Active measures must be taken to prevent the spread of drug-resistant TB in Poland and potentially, the rest of Europe