To the Editors:
Lithuania, a high-priority country for tuberculosis (TB) control in the World Health Organization European Region, has one of the world’s highest rates of multidrug-resistant (MDR)-TB. It has recently seen an increase in the rates of both primary and acquired MDR-TB (9% of new and 50% of re-treatment cases were MDR in 2010), and the appearance of extensively drug-resistant (XDR)-TB cases constituting 4.3% of all MDR-TB cases [1, 2]. Drug resistance is accompanied by low treatment success rates (40% in newly diagnosed and 19% in re-treatment cases in 2009) among MDR-TB patients despite a well-established TB control programme with relatively good indicators of treatment success and low default rates (7%) among patients with sensitive TB [2].
Although there are data describing the molecular epidemiology of drug resistance in Lithuania [3], relatively little is known about risk factors for drug resistance. We analysed 7 yrs of Lithuanian national surveillance data: all treated culture-confirmed TB cases, including new and re-treatment cases, registered from 2002 to 2008 in the national TB register (established in 2002). Our aim was to describe the epidemiological, clinical and socioeconomic features of MDR-/XDR-TB cases, and to establish risk factors for drug resistance acquisition and development during re-treatment.
Standard case reporting included demographic and clinical information with initial and follow-up drug susceptibility testing (DST) results. Individual patients suspected of having a high risk of HIV/AIDS were offered testing for HIV according to the national policy. A randomly selected proportion of strains (∼18%) was genotyped (by IS6110 restriction fragment length polymorphism typing and spoligotyping) within the routine service …
