First-line anti-tuberculosis drug resistance patterns and trends at the national TB referral center in Iran—eight years of surveillance

SummaryObjectiveResistance to anti-tuberculosis (anti-TB) drugs is becoming a major and alarming threat in most regions worldwide.MethodsThis was a descriptive cross-sectional study at a tertiary hospital in Iran, using patient medical records for 2000–2003. The findings were analyzed following the same framework as that used for previous reports from this center.ResultsAmong 1556 TB patients, drug susceptibility testing (DST) was performed for 548 culture-positive cases. Anti-TB drug resistance to both isoniazid and rifampin was identified in 10 (2.8%) of the new TB cases (multidrug-resistant TB; MDR-TB). Any resistance was detected in 228 (41.6%), showing an increasing trend in both new and retreatment cases. The data analysis revealed that drug-resistant TB had a statistically significant association with Afghan ethnicity, age >65 years, and the type of disease (retreatment vs. new TB case) (p