DRUG-SUSCEPTIBILITY PATTERN OF MYCOBACTERIUM TUBERCULOSIS AMONG PULMONARY TUBERCULOSIS PATIENTS IN RIYADH, SAUDI ARABIA

OBJECTIVE: To identify the pattern of drug-susceptibility of newly diagnosed pulmonary tuberculosis patients in Riyadh, we conducted a study on all Mycobacterium tuberculosis positive-culture patients admitted to Sahari Chest Hospital from January 1994 to April 1995. METHODS: Demographic data, antituberculous therapy and drug-susceptibility testing results of each patient were reviewed from patients′ hospital records. The samples were cultured on Lowenstein-Jensen media and drug susceptibility was tested by Bactec 12B (Middlebrook 7H12) media against selected antituberculous drugs RESULTS: Drug susceptibility was performed on 362 (91%) of the sputum positive-cultures. The overall initial resistance rate (1 or more drugs) was 12.4%. Initial. resistance was more common with a single drug (9.4%), followed by two drugs (2.3%) and then three drugs (0.3%). Resistance to isoniazid was most common (10.4%), followed by streptomycin (2.7%), rifampicin (1.9%) and ethambutol (0.6%). Single isoniazid resistance was 60%, followed by two drugs: streptomycin and isoniazid (13.3%). CONCLUSION AND RECOMMENDATIONS: Resistance to multiple drugs is not yet a significant problem in Riyadh. A continuous monitoring of drug resistance is important for planning and assessing the national TB control program. Timely and complete reporting is essential to identify the problem as and when it begins.