[Drug resistance in endemic and imported tuberculosis cases in Sicily (Italy)]

This study was performed to evaluate the prevalence of anti-tuberculosis (TB) drug resistance in Sicily (Italy). A total of 92 Mycobacterium tuberculosis strains were tested, 43 of which were isolated from outpatients between 2004 and 2007 and 49 isolated from patients hospitalized in various eastern Sicilian hospitals. The 92 strains were all isolated from adult patients (mean age 56 years), 71 of which were Italian and the remaining 21non-Italian. Drug sensitivity testing was performed by using the Canetti proportion method and revealed a large proportion of strains (48.9%) found to be resistant to one or more drugs. The most frequent type of resistance was found to be towards rifampicin (38%). Simultaneous resistance to rifampicin and isoniazid, which characterizes multi-drug resistant TB (MDR-TB), was observed in 19.5% of strains; this was always associated with resistance to at least one other anti-tuberculosis drug. No significant differences were found in the distribution of drug resistance, including multi-drug resistance, between strains isolated from Italian and non-Italian patients. A higher percentage of resistance was found amongst strains isolated from hospitalized patients with respect to those from outpatients: rifampicin 53% vs 21%; isoniazid 41% vs 9%; Mdr-TB 47% vs 12%.