Anti-tuberculosis drug resistance in Portugal

SETTING: A survey based upon a representative sample of smear-positive pulm onary tuberculosis patients was undertaken in Portugal, as part of the Worl d Health Organization's Global Project on Anti-Tuberculosis Drug Resistance Surveillance. OBJECTIVE: TO determine the level of primary antituberculosis drug resistan ce at both national and regional levels, and to assess its relative weight within the performance of the National Tuberculosis Programme (NTP). DESIGN: Mycobacterium tuberculosis isolates from 1105 patients with smear-p ositive pulmonary tuberculosis admitted to 46 randomly stratified treatment centres all over mainland Portugal were submitted to susceptibility testin g with four drugs. Human immunodeficiency virus (HIV) testing was included in the patients' evaluation scheme. RESULTS: Of the strains isolated, 197 (17.8%) were resistant to at least on e drug. Primary resistance to isoniazid was 7.7% and to rifampicin 1.9%. Ac quired drug resistance was 39.2% in total, any acquired resistance to isoni azid 31.1% and to rifampicin 20.9%. Primary multidrug resistance (MDR) was 1.8% and acquired MDR was 20.9%. HIV testing was positive in 29.2% of MDR-T B cases. CONCLUSIONS: Drug resistance in Portugal is high. Primary MDR and particula rly acquired MDR occur in a high proportion of cases, indicating a need for improvement in NTP performance.