Updated Guidelines for the Management of Asymptomatic Bacteriuria

The Infectious Disease Society of America has published updated guidelines for the management of asymptomatic bacteriuria (ASB) in Clinical Infectious Diseases. The update includes recommendations for previously unaddressed populations and relevant interpretations on nonlocalizing clinical symptoms in groups with high asymptomatic bacteriuria prevalence.

Asymptomatic bacteriuria is a common finding in healthy female populations and in many women or men with abnormalities of the genitourinary tract that obstruct urination. It is characterized as “the presence of 1 or more species of bacteria growing in the urine at specified quantitative counts (≥105 colony-forming units [CFU]/mL or ≥108 CFU/L), irrespective of the presence of pyuria, in the absence of signs or symptoms attributable to urinary tract infection.” The previous guidelines, published in 2005, recommended screening for and treatment in pregnant women or persons about to undergo invasive urologic procedures. Since the original publication, new evidence concerning asymptomatic bacteriuria is now available and antimicrobial stewardship programs identified nontreatment of asymptomatic bacteriuria as an important opportunity for decreasing inappropriate antimicrobial use.

The updated guidelines made recommendations against screening and treatment for several patient populations, including pediatric patients, healthy premenopausal women, nonpregnant women or healthy postmenopausal women, older community-dwelling persons who are functionally impaired, older persons residing in long-term care facilities, patients with non-renal solid organ transplants, and renal transplant recipients who have had renal transplant surgery >1 month prior. Screening is also not recommended for patients with diabetes, spinal cord injury, short-term and long-term indwelling urethral catheters, those undergoing elective non-urologic surgery or surgery for an artificial urine sphincter or penile prosthesis implantation.

Populations recommended for screening and treatment included pregnant women, in which the suggested treatment was 4 to 7 days of antimicrobial agents, rather than a shorter duration. Screening was also recommended for patients scheduled to undergo endoscopic urologic procedures associated with mucosal trauma. For this population, screening and treating of asymptomatic bacteriuria prior to surgery was recommended. For those undergoing endoscopic urologic procedures, it is suggested that a urine culture be obtained prior to the procedure and targeted antimicrobial therapy prescribed rather than empiric therapy. For patients with asymptomatic bacteriuria who will undergo any urologic procedure, a short course of 1 or 2 doses was advised, as opposed to prolonged antimicrobial therapy.

For older patients with functional and/or cognitive impairment who have bacteriuria and delirium, but who do not have local genitourinary symptoms or other systemic signs of infection, it is recommended that assessments for other causes and careful observation be used in place of antimicrobial treatment. The report could not make a recommendation for or against the screening of patients with high-risk neutropenia (defined as absolute neutrophil count <100 cells/mm3 for ≥7 days) following chemotherapy.

The weight of evidence behind all of these recommendations varies and is summarized in the full report. The report also provided strength of both the recommendation and evidence for each amendment to the guideline. The study investigators also noted that, “current recommendations for treatment of ASB prior to urologic device implantation are based on the results of a single retrospective study,” and that further, prospective studies of a high methodologic quality are needed for validation.

Reference

Nicolle LE, Gupta K, Bradley SF, et al. Clinical practice guideline for the management of asymptomatic bacteriuria: 2019 update by the Infectious Diseases Society of America [published online March 21, 2019]. Clin Infect Dis. doi: 10.1093/cid/ciy1121