Daily trimethoprim-sulfamethoxazole prophylaxis rapidly induces corresponding resistance among intestinal Escherichia coli of HIV-infected adults in Kenya.

BACKGROUND

Trimethoprim-sulfamethoxazole (TMP-SMZ) has been recommended by World Health Organization (WHO) as daily prophylaxis for Africans with AIDS to prevent opportunistic infections. Daily TMP-SMZ may reduce its susceptibility to commensal intestinal Escherichia coli (E coli), increasing the burden of TMP-SMZ-resistant pathogens.

METHODS

Participants received either daily TMP-SMZ (CD4 <350 cells/mm(3)) or daily multivitamins (MVIs; CD4 > or =350 cells/mm(3)) for 6 months. Stool was collected at baseline, 2 weeks, 2 months, and 6 months. A random E coli was tested for susceptibility.

RESULTS

Baseline prevalence of TMP-SMZ resistance ranged from 71% to 81% and was not different across CD4 strata. At 2 weeks, prevalence of TMP-SMZ-resistant E coli increased significantly from 78% to 98% (P < .001) among persons taking daily TMP-SMZ and did not change among persons taking MVIs.

CONCLUSIONS

Daily prophylaxis with TMP-SMZ induced in vivo resistance to the drug after 2 weeks. Empiric therapy for diarrhea with agents other than TMP-SMZ should be considered for HIV-infected persons receiving daily TMP-SMZ prophylaxis.