Drug-resistant tuberculosis in HIV-infected persons: Italy 1999-2000.

BACKGROUND: Patients with HIV infection may be a valuable target for assessing the impact of drug-resistant tuberculosis (TB). PATIENTS AND METHODS: An observational, prospective study was conducted in 96 infectious disease hospital units in Italy during 1999-2000. A total of 140 HIV-infected patients with diagnosis of TB and with an isolate tested for drug susceptibility entered the analysis. Drug resistance (DR) was defined as resistance to either isoniazid (INH) or rifampin (RIF), while multidrug resistance (MDR) was defined as resistance to INH and RIF. RESULTS: A total of 117 (83.6%) episodes of TB were classified as new cases and 23 (16.4%) as previously treated cases. Prevalence of resistance to INH or RIF was 12.8% and 4.3% among new cases, and 17.4% and 26.1% among previously treated cases, respectively. Prevalence rates of DR and MDR were 14.5% and 2.6% among new cases and 30.4% and 12.5% among previously treated cases, respectively. No statistically significant risk factors associated with DR or MDR TB emerged in this analysis. CONCLUSION: High prevalence rates of DR and MDR are present among HIV-infected TB patients in Italy, in particular among previously treated cases.