Mycobacterium tuberculosis drug resistance in Turkey, 1976-97

Drug-resistant tuberculosis is increasing day by day and is a significant t hreat to tuberculosis control because there are few drugs effective against Mycobacterium tuberculosis. This study evaluates the resistance of the mic roorganism to primary anti-tuberculosis drugs over the 21-y period 1976-97. Records from the bacteriology laboratory of the Department of Chest Diseas es and Tuberculosis, Ankara University Medical Faculty were evaluated retro spectively. Among 3,418 mycobacteria strains, 3,319 (97.1%) M, tuberculosis were isolated and their susceptibility was examined by the proportion meth od in Loewenstein-Jensen medium. It was found that 60.8% of isolated strain s were susceptible, whereas 39.2% were resistant to at least one drug. Mult i-drug resistant tuberculosis (MDR-TB) was found in 194 (5.8%) materials. O ver the 21-y period studied, total resistance to isoniazid (INH), rifampici n (RF) and streptomycin (SNI) were determined as 10.5, 6.9 and 7.0%, respec tively. It was also observed that the resistance rates to INH or SM increas ed, whereas resistance to RF was not changed within this period. While resi stance to the 2-drug combination RF+SM increased, resistance to INH+SM decr eased significantly. There was no change in resistance to the 2-drug INH+RF or 3-drug INH+RF+SM combinations in the same period. In conclusion, combin ed therapy is still useful and available for the treatment of resistant tub erculosis, and INH should be included in the chemotherapeutic regimen even if high resistance rates are shown to exist.