Infectious Diseases Society of America Guidelines for the Diagnosis and Treatment of Asymptomatic Bacteriuria in Adults

Abstract

1. The diagnosis of asymptomatic bacteriuria should be based on results of culture of a urine specimen collected in a manner that minimizes contamination (A-II) (table 1). Infectious Diseases Society of America—US Public Health Service Grading System for ranking recommendations in clinical guidelines. • For asymptomatic women, bacteriuria is defined as 2 consecutive voided urine specimens with isolation of the same bacterial strain in quantitative counts ⩾105 cfu/mL (B-II). • A single, clean-catch voided urine specimen with 1 bacterial species isolated in a quantitative count ⩾105 cfu/mL identifies bacteriuria in men (B-III). • A single catheterized urine specimen with 1 bacterial species isolated in a quantitative count ⩾102 cfu/mL identifies bacteriuria in women or men (A-II). 2. Pyuria accompanying asymptomatic bacteriuria is not an indication for antimicrobial treatment (A-II). 3. Pregnant women should be screened for bacteriuria by urine culture at least once in early pregnancy, and they should be treated if the results are positive (A-I). • The duration of antimicrobial therapy should be 3–7 days (A-II). • Periodic screening for recurrent bacteriuria should be undertaken following therapy (A-III). • No recommendation can be made for or against repeated screening of culture-negative women in later pregnancy. 4. Screening for and treatment of asymptomatic bacteriuria before transurethral resection of the prostate is recommended (A-I). • An assessment for the presence of bacteriuria should be obtained, so that results will be available to direct antimicrobial therapy prior to the procedure (A-III). • Antimicrobial therapy should be initiated shortly before the procedure (A-II). • Antimicrobial therapy should not be continued after the procedure, unless an indwelling catheter remains in place (B-II). 5. Screening for and treatment of asymptomatic bacteriuria is recommended before other urologic procedures for which mucosal bleeding is anticipated (A-III). 6. Screening for or treatment of asymptomatic bacteriuria is not recommended for the following persons. • Premenopausal, nonpregnant women (A-I). • Diabetic women (A-I). • Older persons living in the community (A-II). • Elderly, institutionalized subjects (A-I). • Persons with spinal cord injury (A-II). • Catheterized patients while the catheter remains in situ (A-I). 7. Antimicrobial treatment of asymptomatic women with catheter-acquired bacteriuria that persists 48 h after indwelling catheter removal may be considered (B-I). 8. No recommendation can be made for screening for or treatment of asymptomatic bacteriuria in renal transplant or other solid organ transplant recipients (C-III). The purpose of this guideline is to provide recommendations for diagnosis and treatment of asymptomatic bacteriuria in adult populations >18 years of age. The recommendations were developed on the basis of a review of published evidence, with the strength of the recommendation and quality of the evidence graded using previously described Infectious Diseases Society of America (IDSA) criteria (table 1) [1]. Recommendations are relevant only for the treatment of asymptomatic bacteriuria and do not address prophylaxis for prevention of symptomatic or asymptomatic urinary infection. This guideline is not meant to replace clinical judgment. Screening of asymptomatic subjects for bacteriuria is appropriate if bacteriuria has adverse outcomes that can be prevented by antimicrobial therapy [2]. Outcomes of interest are short term, such as symptomatic urinary infection (including bacteremia with sepsis or worsening functional status), and longer term, such as progression to chronic kidney disease or hypertension, development of urinary tract cancer, or decreased duration of survival. Treatment of asymptomatic bacteriuria may itself be associated with undesirable outcomes, including subsequent antimicrobial resistance, adverse drug effects, and cost. If treatment of bacteriuria is not beneficial, screening of asymptomatic populations to identify bacteriuria is not indicated, unless performed in a research study to further explore the biology or clinical significance of bacteriuria. Thus, there are 2 topics of interest: whether asymptomatic bacteriuria is associated with adverse outcomes, and whether the interventions of screening and antimicrobial treatment improve these outcomes. “Asymptomatic bacteriuria,” or asymptomatic urinary infection, is isolation of a specified quantitative count of bacteria in an appropriately collected urine specimen obtained from a person without symptoms or signs referable to urinary infection [3]. “Acute uncomplicated urinary tract infection” is a symptomatic bladder infection characterized by frequency, urgency, dysuria, or suprapubic pain in a woman with a normal genitourinary tract, and it is associated with both genetic and behavioral determinants [4]. “Acute nonobstructive pyelonephritis” is a renal infection characterized by costovertebral angl