Nationwide study of drug resistance among acid-fast bacilli positive pulmonary tuberculosis cases in Lebanon.

OBJECTIVE: To assess the prevalence of drug resistance among smear-positive sputum specimens from pulmonary tuberculosis (TB) cases in Lebanon. DESIGN: Between July 2002 and April 2004, 224 newly diagnosed TB cases and 21 previously treated TB cases were collected nationwide. Mycobacterium tuberculosis isolates were tested against isoniazid (INH), rifampicin (RMP), streptomycin (SM) and ethambutol (EMB) using the BACTEC-TB system. RESULTS: M. tuberculosis and non-tuberculous mycobacteria (NTM) isolates were recovered from 190 and 15 new cases, respectively, and from 16 and 1 previously treated cases, respectively. Overall drug resistance among new TB vs. previously treated TB cases was 19.5% and 75%, and for single drugs it was INH (12% vs. 63%), RMP (3% vs. 56%), SM (12% vs. 44%) and EMB (3% vs. 44%). The overall rate of multidrug resistance (MDR) was 5.8% (1% vs. 62.5%). The male:female ratio was 1.3:1; most were young adults. CONCLUSION: Relatively moderate single drug resistance and very low MDR rates were found among new TB cases, while among previously treated TB cases very high resistance and MDR resistance rates were detected. Such findings underline the need for ongoing stringent control measures to curb the spread of M. tuberculosis and its deleterious effects.