RT Journal Article SR Electronic T1 Clinical and operational value of the extensively drug-resistant tuberculosis definition JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 623 OP 626 DO 10.1183/09031936.00077307 VO 30 IS 4 A1 G. B. Migliori A1 G. Besozzi A1 E. Girardi A1 K. Kliiman A1 C. Lange A1 O. S. Toungoussova A1 G. Ferrara A1 D. M. Cirillo A1 A. Gori A1 A. Matteelli A1 A. Spanevello A1 L. R. Codecasa A1 M. C. Raviglione A1 SMIRA/TBNET Study Group YR 2007 UL http://erj.ersjournals.com/content/30/4/623.abstract AB Currently, no information is available on the effect of resistance/susceptibility to first-line drugs different from isoniazid and rifampicin in determining the outcome of extensively drug-resistant tuberculosis (XDR-TB) patients, and whether being XDR-TB is a more accurate indicator of poor clinical outcome than being resistant to all first-line anti-tuberculosis (TB) drugs. To investigate this issue, a large series of multidrug-resistant TB (MDR-TB) and XDR-TB cases diagnosed in Estonia, Germany, Italy and the Russian Federation during the period 1999–2006 were analysed. Drug-susceptibility testing for first- and second-line anti-TB drugs, quality assurance and treatment delivery was performed according to World Health Organization recommendations in all study sites. Out of 4,583 culture-positive TB cases analysed, 361 (7.9%) were MDR and 64 (1.4%) were XDR. XDR-TB cases had a relative risk (RR) of 1.58 to have an unfavourable outcome compared with MDR-TB cases resistant to all first-line drugs (isoniazid, rifampicin ethambutol, streptomycin and, when tested, pyrazinamide), and an RR of 2.61 compared with “other” MDR-TB cases (those susceptible to at least one first-line anti-TB drug among ethambutol, pyrazinamide and streptomycin, regardless of resistance to the second-line drugs not defining XDR-TB). The emergence of extensively drug-resistant tuberculosis confirms that problems in tuberculosis management are still present in Europe. While waiting for new tools which will facilitate management of extensively drug-resistant tuberculosis, accessibility to quality diagnostic and treatment services should be urgently ensured and adequate public health policies should be rapidly implemented to prevent further development of drug resistance.