Presence of 1 or more bacteria ≥10⁵ CFU/mL with no UTI symptoms

• Often suspected to be one of the non-specific symptoms caused by UTI
• Treating ASB in patients with delirium has not shown any beneficial impact in clinical outcomes compared to no treatment (See Relevant Studies below)

Assess for other causes (i.e. dehydration) and ‘watch-and-wait’ rather than antimicrobial treatment in:

• Older patients with functional and/or cognitive impairment with bacteriuria and delirium (acute mental status change, confusion), and/or
• Older patients who experience a fall and without local genitourinary symptoms or other systemic signs of infection

Initiating empiric antibiotics for potential UTI may be appropriate pending culture results

1. IDSA 2019. Clinical Practice Guideline for the Management of Asymptomatic Bacteriuria: 2019 Update by the Infectious Disease Society of America.
2. Potts L et al. A double-blind comparative study of norfloxacin versus placebo in hospitalized elderly patients with asymptomatic bacteriuria. Arch Gerontol Geriatr. 1996;23(2):153-61.
3. Silver SA, Baillie L, Simor AE. Positive urine cultures: a major cause of inappropriate antimicrobial use in hospitals? Can J Infect Dis Med Microbiol 2009; 20:107–11.
4. Woodford HJ et al. Diagnosis and management of urinary tract infection in hospitalized older people. J Am Geriatr Soc. 2009;57(1):107-14.
5. Dasgupta M, Brymer C, Elsayed S. Treatment of asymptomatic UTI in older delirious medical in-patients: a prospective cohort study. Arch Gerontol Geriatr 2017; 72:127–34
6. Petty LA et al. Risk Factors and Outcomes Associated with Treatment of Asymptomatic Bacteriuria in Hospitalized Patients. JAMA Intern Med. 2019. 26;179(11):1519-1527
7. Mayne, S., Bowden, A., Sundvall, P. et al. The scientific evidence for a potential link between confusion and urinary tract infection in the elderly is still confusing - a systematic literature review. BMC Geriatr 19, 32 (2019). https://doi.org/10.1186/s12877-019-1049-7