Susceptibility pattern and epidemiology of Mycobacterium tuberculosis in a Saudi Arabian hospital: a 15-year study from 1989 to 2003.

Objectives: The objective of this study was to examine the prevalence and trends of drug resistance of Mycobacterium tuberculosis at the Saudi Aramco Medical Services Organization.

Methods: We retrospectively identified M tuberculosis isolates from January 1989 to December 2003. Antimicrobial susceptibility and clinical data were collected and analyzed.

Results: From 1989 to 2003, 276 nonrepetitive culture-positive cases were identified. There were 236 Saudis (84.6%), and the remainder were non-Saudis (15.4%). M tuberculosis isolates were obtained from pulmonary specimens (49%) and extrapulmonary sites (51%). The resistance rates of M tuberculosis to tested first-line agents were as follows: isoniazid, 12.5%; ethambutol, 7.5%; streptomycin; 6.9%; and rifampin, 1.1%. The resistance rate to isoniazid and streptomycin was 1.8%, the rate to isoniazid and rifampin was 0.7%, and the rate to isoniazid and ethambutol was 2.5%. The resistance rate to isoniazid, ethambutol, and streptomycin was 0.7%

Conclusion: M tuberculosis resistance to isoniazid showed a decreased rate over the study period from 20 to 5.7%. The rate of multidrug-resistant M tuberculosis remained low.