Primary antimicrobial resistance among Mycobacterium tuberculosis isolates from HIV seropositive and HIV seronegative patients in Dar es Salaam Tanzania

BACKGROUND: The United Republic of Tanzania is one of the 22 high M. tuberculosis burden countries. Data collected between 2002 and 2007 indicate that the global prevalence of drug-resistant M. tuberculosis including MDR vary greatly. The varied drug-resistance patterns make continuous surveillance of drug resistance an essential component of tuberculosis control program. FINDINGS: M. tuberculosis isolates were obtained from consenting adult tuberculosis patients involved in a placebo-controlled study to evaluate the efficacy of multivitamin supplements on response to anti-Tb treatment in Dar es Salaam, Tanzania. Antimicrobial susceptibility testing was done on four antimicrobial agents namely streptomycin, isoniazid, ethambutol and rifampicin. HIV testing and CD4+ T lymphocytes enumeration were also done. A total of 280 M. tuberculosis isolates from 191 (68%) males and 89 (32%) female patients with no previous history of anti-tuberculosis treatment exceeding 4 weeks in the previous 12 months were tested. Among these, 133 (47%) patients were HIV seropositive. Fourteen (5.0%) isolates were resistant to any of the anti-tuberculosis drugs. The prevalence of primary resistance was 5.0%, 0.7%, 0.4% and 0% for isoniazid, streptomycin, rifampicin and ethambutol respectively. One isolate (0.4%) was MDR, with resistance to isoniazid, streptomycin and rifampicin. CONCLUSION: M. Tb primary resistance rate in a selected population in Dar es Salaam Tanzania is low and efforts should be undertaken to support the Tuberculosis program.