Antimicrobial treatment in diabetic women with asymptomatic bacteriuria

Asymptomatic bacteriuria is common among women with diabetes, and the treatment of such infections has been recommended to prevent complications related to symptomatic urinary tract infection.

We enrolled women (>16 years of age) with diabetes, bacteriuria (> or =105 colony-forming units of an organism per milliliter in cultures of two consecutive urine specimens), and no urinary symptoms; 50 were randomly assigned to receive placebo and 55 to receive antimicrobial therapy. For the first six weeks, which included the initial course of treatment, the study was placebo-controlled and double-blind. Subsequently, the women were screened for bacteriuria every three months for up to three years; antimicrobial therapy was provided to women in the antimicrobial-therapy group who had asymptomatic bacteriuria.

Four weeks after the end of the initial course of therapy, 78 percent of placebo recipients had bacteriuria, as compared with 20 percent of women who received antimicrobial agents (P<0.001). During a mean follow-up of 27 months, 20 of 50 women in the placebo group (40 percent) and 23 of 55 women in the antimicrobial-therapy group (42 percent) had at least one episode of symptomatic urinary tract infection. The time to a first symptomatic episode was similar in the placebo group and the antimicrobial-therapy group (P=0.67 by the log-rank test), as were the (+/-SD) rates of any symptomatic urinary tract infection (1.10+/-0.17 and 0.93+/-0.14 per 1000 days of follow-up, respectively; relative risk, 1.19; 95 percent confidence interval, 0.28 to 1.81), pyelonephritis (0.28+/-0.08 and 0.13+/-0.05 per 1000 days of follow-up; relative risk, 2.13; 95 percent confidence interval, 0.81 to 5.62), and hospitalization for urinary tract infection (0.10+/-0.36 and 0.06+/-0.22 per 1000 days of follow-up; relative risk, 1.93; 95 percent confidence interval, 0.47 to 7.89). The women in the antimicrobial-therapy group had almost five times as many days of antibiotic use for urinary tract infection as did the women in the placebo group (158.2+/-1.7 vs. 33.7+/-0.91 per 1000 days of follow-up; relative risk, 0.21; 95 percent confidence interval, 0.20 to 0.22).

Treatment of asymptomatic bacteriuria in women with diabetes does not appear to reduce complications. Diabetes itself should not be an indication for screening for or treatment of asymptomatic bacteriuria.