Should an asymptomatic patient colonized with ESBL-producing bacteria and signs of inflammation be treated for UTI?

Do Not Treat This Asymptomatic Patient

You should not treat this patient's bacteriuria, even with ESBL colonization and elevated WBC/leukocytes, because they are asymptomatic and McGeer's criteria specifically require localizing genitourinary symptoms or systemic signs of infection to diagnose UTI. 1

Understanding Asymptomatic Bacteriuria vs. UTI

The critical distinction here is that asymptomatic bacteriuria (ASB) is not a UTI and does not warrant treatment in the vast majority of clinical scenarios. 1

• ASB is defined as isolation of bacteria in appropriately collected urine from a person without symptoms or signs referable to urinary infection 2
• The presence of pyuria (elevated leukocytes) and bacteriuria alone, without symptoms, does not constitute a UTI requiring treatment 1, 3
• ESBL colonization status does not change this recommendation - colonization is not infection 1

Why Treatment Causes More Harm Than Good

The IDSA 2019 guidelines provide strong evidence (strong recommendation, moderate-to-high quality evidence) against treating ASB because:

• Treatment does not prevent symptomatic UTI or other adverse outcomes 1
• Treatment promotes early recurrence with more resistant bacterial strains, including increased ESBL and fluoroquinolone resistance 1, 2
• Treatment increases risk of Clostridioides difficile infection 1
• Treatment causes adverse drug effects without demonstrable benefit 1, 2
• Antimicrobial stewardship principles strongly discourage treating ASB to prevent further resistance development 1, 4

McGeer's Criteria Require Symptoms

For a UTI diagnosis requiring treatment, patients must have:

• Localizing genitourinary symptoms (dysuria, urgency, frequency, suprapubic pain, costovertebral angle tenderness, gross hematuria) OR
• Systemic signs of infection (fever >38°C, hemodynamic instability) 1, 3

Your patient has neither, making this ASB, not UTI.

The ESBL Colonization Factor

While ESBL colonization is a risk factor for ESBL infection when symptomatic infection occurs, it does not justify treating asymptomatic bacteriuria:

• ESBL colonization is common and does not require treatment 1
• Known ESBL colonization should guide empiric therapy selection if symptomatic UTI develops, but does not indicate treatment of ASB 1
• Treating ASB in ESBL-colonized patients further promotes resistance without clinical benefit 1, 2

Common Pitfall to Avoid

Do not obtain urine cultures in asymptomatic patients - a positive culture often inappropriately triggers antimicrobial use regardless of symptoms. 1, 2 The elevated WBC (22,000) and leukocyturia (100,000) likely prompted the urine culture, but these findings alone without genitourinary symptoms do not indicate UTI.

When to Reassess

Monitor for development of:

• Fever (>38°C or 100.4°F)
• New dysuria, urgency, frequency
• Suprapubic or flank pain
• Hemodynamic instability
• Altered mental status with no other explanation (though even this alone doesn't warrant treatment per IDSA guidelines) 1

If any of these develop, then obtain urine culture and treat as symptomatic UTI with ESBL-appropriate antibiotics (carbapenems, ceftazidime-avibactam, or based on susceptibilities). 1, 4, 5

Rare Exceptions Where ASB Treatment Is Indicated

Treatment of ASB is recommended only in:

• Pregnant women 1, 2
• Prior to urologic procedures where mucosal bleeding is anticipated 1, 2

Your patient does not meet either exception.