Criteria & Principles
No known structural abnormalities and lack signs/symptoms of upper tract infection (fever, flank pain) in females.
Diagnostic guidance in interpreting urinalysis and culture are available here and here.
For patients without localizing urinary symptoms, asymptomatic bacteriuria guidance can be found here.
Risks Associated with Treating Asymptomatic Bacteriuria (ASB)
What is ASB? Presence of bacteria in the urine irrespective of pyuria (ex: WBC >10) and without urinary symptoms.2
How common is ASB? Occurs in >15% of women and men older than 70 years old and continues to increase after age 80. It is extremely common in spinal cord injuries including up to 89% with intermittent catheter use and 100% with long-term indwelling catheter.3
Who should be treated for ASB? Pregnant women and patients undergoing endourologic procedures due to fetal benefit and concern for translocation of bacteria during surgery, respectively. There is currently no consensus on the management of ASB in high-risk febrile neutropenia and patients within 1 month of kidney transplant.2
Harm of treating ASB: Consequences of treating ASB include increased risk for antibiotic resistance, adverse effects (8-fold increase for C. difficile infection), risk for future symptomatic UTIs, and healthcare costs without benefit in patient care outcomes.4,5
NOTE: In 2023, 66% (43/65) of DUH patients who received antibiotics for a UTI indication and subsequently developed C. difficile were deemed to have been inappropriately treated for ASB
Treatment
Severity
All Severity
- Nitrofurantoin (Macrobid) 100mg PO BID x 5 days
Alternative agents:
- Cefuroxime 250 mg PO BID x 7 days
- Fosfomycin 3g PO single dose (reserve for MDRO; ID telephone approval required)
Diagnosis-Specific Information
The choice between these agents should be individualized and based on patient allergy, renal function, and compliance or previous use history.
For "treat and release" ED patients use the following treatment strategy (full pocket card attached to the right).
NOTE: Fosfomycin is restricted to ID telephone approval
References
- Gupta K. International Clinical Practice Guidelines for the Treatment of Acute Uncomplicated Cystitis and Pyelonephritis in Women: A 2010 Update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clin Infec Dis 2011;52:e103-e120.
- 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. Clin Infect Dis. 2019 May 2;68(10):e83-e110
- Luu T, Albarillo FS. Asymptomatic Bacteriuria: Prevalence, Diagnosis, Management, and Current Antimicrobial Stewardship Implementations. Am J Med. 2022 Aug;135(8):e236-e244.
- Cai T, Mazzoli S, Mondaini N, et al. The Role of Asymptomatic Bacteriuria in Young Women with Recurrent Urinary Tract Infections: To Treat or Not to Treat?” Clin Infect Dis. 2015 Sept 15;55(6):e771-777
- Rotjanapan P, Dosa D, Thomas KS. Potentially inappropriate treatment of urinary tract infections in two Rhode Island nursing homes. Arch Intern Med. 2011;171(5):438-443.