Extensively drug-resistant tuberculosis – first report of a case in Austria, May 2008

We report on the first documented extensively drug-resistant tuberculosis (XDR-TB) case in Austria, diagnosed this year. The term XDR-TB was used for the first time in March 2006, in a report jointly published by the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) to describe a disease caused by Mycobacterium tuberculosis that was resistant not only to isoniazid and rifampicin (i.e. multi-drug resistant tuberculosis, MDR-TB), but also to at least three of the six classes of second-line anti-TB drugs - aminoglycosides, polypeptides, fluoroquinolones, thioamides, cycloserine, and para-aminosalycilic acid [1,2]. As this definition was dependent on unstandardised drug susceptibility testing (DST) methodologies and did not necessarily distinguish the most difficult-to-treat cases using the current drug armamentarium, it was eventually modified in October 2006 [1]. XDR-TB is now defined as: resistance to at least rifampicin and isoniazid, in addition to any fluoroquinolone, and to at least one of the three following injectable drugs used in anti-TB treatment: capreomycin, kanamycin, and amikacin [3]. .