Drug resistance in tuberculosis is a serious threat to national TB programs throughout the world, but particularly in a developing country. 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.
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.
Drug susceptibility was performed on 362 (91%) of the sputum positive culture. 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 2 drugs (2.3%) and then 3 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 2 drugs streptomycin and isoniazid (13.3%).
Resistance to multiple drugs is not yet a significant problem in Riyadh. A continuous monitoring of drug resistance is important for planning and assessment of national TB control programs. Timely and complete reporting is essential to identify the problem as and when it begins.
Conclusion: