Screening for Asymptomatic Bacteriuria in Adults

Importance

Screening for asymptomatic bacteriuria can identify patients for whom treatment might be beneficial for preventing symptomatic infection and other health outcomes.

Objective

To systematically review benefits and harms of asymptomatic bacteriuria screening and treatment in adults, including during pregnancy, to inform the US Preventive Services Task Force.

Data Sources

MEDLINE, PubMed (publisher-supplied records), and Cochrane Collaboration Central Registry of Controlled Trials; surveillance through May 24, 2019.

Study Selection

Randomized clinical trials (RCTs) and observational studies on benefits and harms of screening for asymptomatic bacteriuria; RCTs on benefits and harms of asymptomatic bacteriuria treatment. Eligible populations included unselected, asymptomatic individuals without known urinary tract conditions.

Data Extraction and Synthesis

Independent critical appraisal and data abstraction by 2 reviewers. Random-effects meta-analysis was conducted to estimate benefits of the interventions.

Main Outcomes and Measures

Symptomatic infection; function, morbidity, mortality; pregnancy complications and birth outcomes.

Results

Nineteen studies (N = 8443) meeting inclusion criteria were identified. Two cohort studies (n = 5289) found fewer cases of pyelonephritis in the cohorts of screened pregnant women (0.5%) than within retrospective comparisons of unscreened cohorts (2.2% and 1.8%); the larger study estimated a statistically significant relative risk of 0.30 (95% CI, 0.15-0.60). No studies examined screening in nonpregnant populations. Among 12 trials of asymptomatic bacteriuria screening and treatment during pregnancy (n = 2377; 1 conducted within past 30 years), there were reduced rates of pyelonephritis (range, 0%-16.5% for the intervention group and 2.2%-36.4% for the control group; pooled risk ratio [RR], 0.24 [95% CI, 0.14-0.40]; 12 trials) and low birth weight (range, 2.5%-14.8% for the intervention group and 6.7%-21.4% for the control group; pooled RR, 0.64 [95% CI, 0.46-0.90]; 7 trials). There was no significant difference in infant mortality (pooled RR, 0.98 [95% CI, 0.29-3.26]; 6 trials). Five RCTs of asymptomatic bacteriuria treatment in nonpregnant adults (n = 777) did not report any significant differences in risk of infection, mobility, or mortality. Limited evidence on harms of screening or treatment was available, and no statistically significant differences were identified.

Conclusions and Relevance

Screening and treatment for asymptomatic bacteriuria during pregnancy was associated with reduced rates of pyelonephritis and low birth weights, but the available evidence was not current, with only 1 study conducted in the past 30 years. Benefits of asymptomatic bacteriuria treatment in nonpregnant adult populations were not found. Trial evidence on harms of asymptomatic bacteriuria antibiotic treatment was limited.