Resistance to antituberculosis drugs has been rising in Botswana since 1995

Aug 4 2005

Resistance to antituberculosis drugs has been rising in Botswana since 1995, concludes a Research Letter in this weeks issue of The Lancet. Enhanced interventions for TB control are urgently needed in Botswana to prevent further emergence of drug resistance, state the authors.

Two surveys undertaken in Botswana in the 1990s have recorded low rates of anti-TB drug resistance (3% of new patients) despite a three-fold increase in TB since 1989. Lisa Nelson (Centers of Disease Control and Prevention, Atlanta, GA, USA) and colleagues undertook a third survey to determine trends since 1995 and HIV prevalence in TB patients in Botswana. From March to November 2002 the investigators analysed 2200 new patients whose sputum samples tested positive for TB bacterium and 219 patients previously treated for TB who were suspected of needing retreatment. The researchers also carried out unlinked anonymous testing of sputum samples to estimate the prevalence of HIV among patients enrolled in the survey. The researchers found that 60% of the group were also infected with HIV. They also found that 10% of new patients were resistant to at least one anti-TB drug.

Dr Nelson states: “The increase in drug resistance in Botswana in new patients with tuberculosis suggests increasing transmission of drug-resistant strains in the community or congregate settings . . . Enhanced interventions are still needed to contain the burden of tuberculosis in Botswana and prevent further drug resistance. These approaches include intensified tuberculosis case finding, control of tuberculosis transmission in congregate setting such as hospitals and prisons, and case management to ensure successful treatment completion.”