Anti-TB drug resistance levels and patterns among Mycobacterium tuberculosis isolated from newly diagnosed cases of pulmonary tuberculosis in Dar es Salaam, Tanzania.

Anti-tuberculosis drug resistance levels and patterns of Mycobacterium tuberculosis (Mtb) isolated from newly diagnosed tuberculosis (TB) patients in Temeke district in Dar es Salaam, Tanzania were investigated. A total of 226 Mtb isolates from 564 TB suspects with no previous history of anti-TB treatment were tested for drug resistance against rifampicin, isoniazid, streptomycin and ethambutol on Lowenstein Jensen (LJ) medium using the proportion method. Of the 226 isolates, 22 (9.7%) were resistant to any one of the four anti-TB drugs; nine (3.99%) isolates were isoniazid mono-drug resistant and eight (3.54%) isolates were streptomycin mono-drug resistant. Multi-drug resistance, defined as resistance to both rifampicin and isoniazid, was observed in three (1.3%) isolates and two were also resistant to streptomycin and ethambutol. One (0.44%) isolate had poly resistance to isoniazid and streptomycin. The level of anti-TB drug resistant Mtb in Temeke, an HIV endemic area, remained constant between 1995 and 2007. The level of resistance to any one of the four anti-TB drugs was between 9.0% and 10%, resistance to individual drugs <4% and multi-drug resistance <2%.