Mariëlle A. J. Beerepoot

Cranberries vs antibiotics to prevent urinary tract infections: a randomized double-blind noninferiority trial in premenopausal women

BACKGROUND The increasing prevalence of uropathogens resistant to antimicrobial agents has stimulated interest in cranberries to prevent recurrent urinary tract infections (UTIs). METHODS In a double-blind, double-dummy noninferiority trial, 221 premenopausal women with recurrent UTIs were randomized to 12-month prophylaxis use of trimethoprim-sulfamethoxazole (TMP-SMX), 480 mg once daily, or cranberry capsules, 500 mg twice daily. Primary end points were the mean number of symptomatic UTIs over 12 months, the proportion of patients with at least 1 symptomatic UTI, the median time to first UTI, and development of antibiotic resistance in indigenous Escherichia coli. RESULTS After 12 months, the mean number of patients with at least 1 symptomatic UTI was higher in the cranberry than in the TMP-SMX group (4.0 vs 1.8; P = .02), and the proportion of patients with at least 1 symptomatic UTI was higher in the cranberry than in the TMP-SMX group (78.2% vs 71.1%). Median time to the first symptomatic UTI was 4 months for the cranberry and 8 months for the TMP-SMX group. After 1 month, in the cranberry group, 23.7% of fecal and 28.1% of asymptomatic bacteriuria E coli isolates were TMP-SMX resistant, whereas in the TMP-SMX group, 86.3% of fecal and 90.5% of asymptomatic bacteriuria E coli isolates were TMP-SMX resistant. Similarly, we found increased resistance rates for trimethoprim, amoxicillin, and ciprofloxacin in these E coli isolates after 1 month in the TMP-SMX group. After discontinuation of TMP-SMX, resistance reached baseline levels after 3 months. Antibiotic resistance did not increase in the cranberry group. Cranberries and TMP-SMX were equally well tolerated. CONCLUSION In premenopausal women, TMP-SMX, 480 mg once daily, is more effective than cranberry capsules, 500 mg twice daily, to prevent recurrent UTIs, at the expense of emerging antibiotic resistance. TRIAL REGISTRATION isrctn.org Identifier: ISRCTN50717094.

Nonantibiotic prophylaxis for recurrent urinary tract infections: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE Increasing antimicrobial resistance has stimulated interest in nonantibiotic prophylaxis of recurrent urinary tract infections. We assessed the effectiveness, tolerability and safety of nonantibiotic prophylaxis in adults with recurrent urinary tract infections. MATERIALS AND METHODS MEDLINE®, EMBASE™, the Cochrane Library and reference lists of relevant reviews were searched to April 2013 for relevant English language citations. Two reviewers selected randomized controlled trials that met the predefined criteria for population, interventions and outcomes. The difference in the proportions of patients with at least 1 urinary tract infection was calculated for individual studies, and pooled risk ratios were calculated using random and fixed effects models. Adverse event rates were also extracted. The Jadad score was used to assess risk of bias (0 to 2-high risk and 3 to 5-low risk). RESULTS We identified 5,413 records and included 17 studies with data for 2,165 patients. The oral immunostimulant OM-89 decreased the rate of urinary tract infection recurrence (4 trials, sample size 891, median Jadad score 3, RR 0.61, 95% CI 0.48-0.78) and had a good safety profile. The vaginal vaccine Urovac® slightly reduced urinary tract infection recurrence (3 trials, sample size 220, Jadad score 3, RR 0.81, 95% CI 0.68-0.96) and primary immunization followed by booster immunization increased the time to reinfection. Vaginal estrogens showed a trend toward preventing urinary tract infection recurrence (2 trials, sample size 201, Jadad score 2.5, RR 0.42, 95% CI 0.16-1.10) but vaginal irritation occurred in 6% to 20% of women. Cranberries decreased urinary tract infection recurrence (2 trials, sample size 250, Jadad score 4, RR 0.53, 95% CI 0.33-0.83) as did acupuncture (2 open label trials, sample size 165, Jadad score 2, RR 0.48, 95% CI 0.29-0.79). Oral estrogens and lactobacilli prophylaxis did not decrease the rate of urinary tract infection recurrence. CONCLUSIONS The evidence of the effectiveness of the oral immunostimulant OM-89 is promising. Although sometimes statistically significant, pooled findings for the other interventions should be considered tentative until corroborated by more research. Large head-to-head trials should be performed to optimally inform clinical decision making.

Prevention of Recurrent Urinary Tract Infections in Women: Antimicrobial and Nonantimicrobial Strategies

Recurrent urinary tract infections (UTIs) are common, especially in women. Low-dose daily or postcoital antimicrobial prophylaxis is effective for prevention of recurrent UTIs and women can self-diagnose and self-treat a new UTI with antibiotics. The increasing resistance rates of Escherichia coli to antimicrobial agents has, however, stimulated interest in nonantibiotic methods for the prevention of UTIs. This article reviews the literature on efficacy of different forms of nonantibiotic prophylaxis. Future studies with lactobacilli strains (oral and vaginal) and the oral immunostimulant OM-89 are warranted.

Non-Antibiotic Prophylaxis for Urinary Tract Infections

Increasing antimicrobial resistance has stimulated interest in non-antibiotic prophylaxis of recurrent urinary tract infections (UTIs). Well-known steps in the pathogenesis of UTIs are urogenital colonization and adherence of uropathogens to uroepithelial cell receptors. To prevent colonization in postmenopausal women, vaginal, but not oral, estrogens have been shown to restore the vagina lactobacilli flora, reduce vaginal colonization with Enterobacteriaceae, and reduce the number of UTIs compared to placebo. Different lactobacilli strains show different results in the prevention of recurrent UTIs. Intravaginal suppositories with Lactobacillus crispatus in premenopausal women and oral capsules with Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 in postmenopausal women are promising. Ascorbic acid (vitamin C) cannot be recommended for the prevention of UTIs. Cranberries are thought to contain proanthocyanidins that can inhibit adherence of P-fimbriated E. coli to the uroepithelial cell receptors. Cranberry products decreased UTI recurrences about 30%–40% in premenopausal women with recurrent UTIs, but are less effective than low-dose antimicrobial prophylaxis. However, the optimal dose of cranberry product has still to be determined. Initially OM-89, a vaccine with 18 heat-killed E. coli extracts, seemed promising, but this was not confirmed in a recently randomized trial.

Determinants of Antimicrobial Resistance in Escherichia coli Strains Isolated from Faeces and Urine of Women with Recurrent Urinary Tract Infections

For women with recurrent urinary tract infections (rUTI), the contribution of antibiotic use versus patient-related factors in determining the presence of antimicrobial resistance in faecal and urinary Escherichia coli, obtained from the same patient population, has not been assessed yet. Within the context of the ‘Non-antibiotic prophylaxis for recurrent urinary tract infections’ (NAPRUTI) study, the present study assessed determinants of antimicrobial resistance in E. coli isolated from urinary and faecal samples of women with rUTIs collected at baseline. Potential determinants of resistance were retrieved from self-administered questionnaires. From 434 asymptomatic women, 433 urinary and 424 faecal samples were obtained. E. coli was isolated from 146 (34%) urinary samples and from 336 (79%) faecal samples, and subsequently tested for antimicrobial susceptibility. Multivariable analysis showed trimethoprim/sulfamethoxazole (SXT) use three months prior to inclusion to be associated with urine E. coli resistance to amoxicillin (OR 3.6, 95% confidence interval: 1.3–9.9), amoxicillin-clavulanic acid (OR 4.4, 1.5–13.3), trimethoprim (OR 3.9, 1.4–10.5) and SXT (OR 3.2, 1.2–8.5), and with faecal E. coli resistance to trimethoprim (OR 2.0, 1.0–3.7). The number of UTIs in the preceding year was correlated with urine E. coli resistance to amoxicillin-clavulanic acid (OR 1.11, 1.01–1.22), trimethoprim (OR 1.13, 1.03–1.23) and SXT (OR 1.10, 1.01–1.19). Age was predictive for faecal E. coli resistance to amoxicillin (OR 1.02, 1.00–1.03), norfloxacin and ciprofloxacin (both OR 1.03, 1.01–1.06). In conclusion, in women with rUTI different determinants were found for urinary and faecal E. coli resistance. Previous antibiotic use and UTI history were associated with urine E. coli resistance and age was a predictor of faecal E. coli resistance. These associations could best be explained by cumulative antibiotic use.

Cost-effectiveness of cranberries vs antibiotics to prevent urinary tract infections in premenopausal women: a randomized clinical trial.

Background Urinary tract infections (UTIs) are common and result in an enormous economic burden. The increasing prevalence of antibiotic-resistant microorganisms has stimulated interest in non-antibiotic agents to prevent UTIs. Objective To evaluate the cost-effectiveness of cranberry prophylaxis compared to antibiotic prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX) over a 12 month period in premenopausal women with recurrent UTIs. Materials and Methods An economic evaluation was performed alongside a randomized trial. Primary outcome was the number of UTIs during 12 months. Secondary outcomes included satisfaction and quality of life. Healthcare utilization was measured using questionnaires. Missing data were imputed using multiple imputation. Bootstrapping was used to evaluate the cost-effectiveness of the treatments. Results Cranberry prophylaxis was less effective than TMP-SMX prophylaxis, but the differences in clinical outcomes were not statistically significant. Costs after 12 months in the cranberry group were statistically significantly higher than in the TMP-SMX group (mean difference €249, 95% confidence interval 70 to 516). Cost-effectiveness planes and cost-effectiveness acceptability curves showed that cranberry prophylaxis to prevent UTIs is less effective and more expensive than (dominated by) TMP-SMX prophylaxis. Conclusion In premenopausal women with recurrent UTIs, cranberry prophylaxis is not cost-effective compared to TMP-SMX prophylaxis. However, it was not possible to take into account costs attributed to increased antibiotic resistance within the framework of this randomized trial; modeling studies are recommended to investigate these costs. Moreover, although we based the dosage of cranberry extract on available evidence, this may not be the optimal dosage. Results may change when this optimal dosage is identified. Trial Registration ISRCTN.org ISRCTN50717094

Rapid assessment of antimicrobial resistance prevalence using a Lot Quality Assurance sampling approach

AIM Increasing antimicrobial resistance (AMR) requires rapid surveillance tools, such as Lot Quality Assurance Sampling (LQAS). MATERIALS & METHODS LQAS classifies AMR as high or low based on set parameters. We compared classifications with the underlying true AMR prevalence using data on 1335 Escherichia coli isolates from surveys of community-acquired urinary tract infection in women, by assessing operating curves, sensitivity and specificity. RESULTS Sensitivity and specificity of any set of LQAS parameters was above 99% and between 79 and 90%, respectively. Operating curves showed high concordance of the LQAS classification with true AMR prevalence estimates. CONCLUSION LQAS-based AMR surveillance is a feasible approach that provides timely and locally relevant estimates, and the necessary information to formulate and evaluate guidelines for empirical treatment.

Women need to know more

Leydon and colleagues found that women attributed urinary tract infection (UTI) to lifestyle habits and behaviours.1 Evidence is accumulating that patient education and counselling are essential for effective prevention in chronic diseases. This is also true for UTI,2 but information about the knowledge of this patient group is limited. We …