Study of drug resistant cases among new pulmonary tuberculosis patients attending a tuberculosis center, Yangon, Myanmar.

A cross-sectional descriptive study was carried out at a tuberculosis center, Yangon, Myanmar from October 2003 to July 2004 to analyze the drug susceptibility of new sputum smear positive pulmonary tuberculosis patients. A total of 202 Mycobacterium tuberculosis isolates were tested for resistance to isoniazid, streptomycin, rifampicin and ethambutol. Resistance to at least one anti-tuberculosis drug was documented in 32 (15.8%) isolates. Monoresistance (resistance to one drug) was noted in 15 (7.4%) isolates and poly-resistance (resistance to two or more drugs) was noted in 17 (9.4%) isolates, including 8 (4.0%) multi-drug resistant isolates (resistance to at least isoniazid and rifampicin). Total resistance to individual anti-tuberculosis drugs were: isoniazid (29, 14.3%), streptomycin (11, 5.4%), rifampicin (10, 4.9%) and ethambutol (1, 0.5%). The demographic data and possible contributing factors of drug resistance were evaluated among the drug resistant patients. Poly-resistant cases had significantly longer intervals between symptom appearance and achieving effective anti-tuberculosis treatment than mono-resistant cases (p = 0.015).