Drug resistance in mycobacterium tuberculosis: a four years experience

ABSTRACT

OBJECTIVE: To assess the prevalence of drug resistance amongst the clinical isolates of M. tuberculosis. SETTING: Armed Forces Institute of Pathology, Rawalpindi. METHOD: Four first line anti-tuberculosis drugs, isoniazid [INH], rifampicin [RIF], ethambutol [ETH] and streptomycin [STR] were tested on 300 isolates from clinical samples, by agar dilution method on Lowenstein Jensen medium. The sensitivities were interpreted by the resistance ratio method. One hundred and fifty eight [52.66%] isolates were found resistant to one drug at least. Among the resistant isolates, 79 [26.33%] were resistant to INH, 72 [24.0%] to RIF, 84 [28.0%] to STR and 70 [23.33%] to ETH with or without resistance to other drugs. Multi-drug resistance [MDR] was found in 41 isolates [13.66%]. To overcome this problem there is a need to establish centres at a number of places all over the country with professionals trained to handle the emerging problem of MDR. Each centre must be equipped with adequate facilities for susceptibility testing so that the resistance pattern can be ascertained and treatment regimens tailored accordingly