Do we treat asymptomatic urinary tract infections (UTIs) in patients, including those with underlying medical conditions or pregnant women?

Treatment of Asymptomatic UTI

Do not treat asymptomatic bacteriuria in the vast majority of patients—the only exceptions are pregnant women and patients undergoing urological procedures that breach the mucosa. 1, 2

Definition and Clinical Context

Asymptomatic bacteriuria (ABU) represents commensal colonization, not infection, and is defined as bacterial growth >10^5 CFU/mL in two consecutive urine samples in women or a single sample in men, without any urinary tract symptoms. 1, 2

• ABU may actually protect against superinfecting symptomatic UTI by preventing colonization with more virulent strains. 1
• Treatment of ABU leads to early recurrence of bacteriuria with more resistant organisms, particularly in catheterized patients. 1

When NOT to Treat (Strong Recommendations)

Do not screen for or treat asymptomatic bacteriuria in the following populations: 1, 2

• Women without risk factors 1
• Postmenopausal women 1
• Elderly institutionalized patients 1
• Patients with well-regulated diabetes mellitus 1
• Patients with dysfunctional or reconstructed lower urinary tract 1
• Patients with neurogenic lower urinary tract dysfunction (NLUTD) 1
• Renal transplant recipients (>1 month post-transplant) 1, 2
• Patients with recurrent UTIs 1—treating ABU in this population is actually harmful, as it eliminates potentially protective bacterial strains 3
• Patients before arthroplasty surgery 1
• Patients before cardiovascular surgeries (weak recommendation) 1
• Healthy premenopausal women 1

When TO Treat (The Only Exceptions)

Pregnant Women (Weak to Moderate Recommendation)

Screen for and treat asymptomatic bacteriuria in pregnant women, preferably in the first trimester. 1, 2

• Use standard short-course treatment (4-7 days) or single-dose fosfomycin trometamol 3g. 1, 2
• Treatment reduces risk of pyelonephritis during pregnancy, low birthweight, and preterm delivery. 3
• This is the only population where treatment of ABU has demonstrated clear clinical benefit. 1, 3

Before Urological Procedures (Strong Recommendation)

Screen for and treat asymptomatic bacteriuria before urological procedures that breach the mucosa. 1, 2

• This includes transurethral resection surgery and upper tract manipulation. 1, 3
• Treatment results in lower risk of postoperative UTI. 3

Rationale for Not Treating

The evidence against treating ABU in most populations is compelling: 1, 2

• No improvement in clinical outcomes: Treatment does not prevent symptomatic UTI, renal scarring, chronic kidney disease, hypertension, or mortality. 1
• Promotes antimicrobial resistance: Unnecessary antibiotic use selects for resistant organisms. 1
• Increases adverse effects: Risk of Clostridioides difficile infection, drug reactions, and allergic responses. 2
• Eliminates protective strains: ABU may prevent colonization with more pathogenic bacteria. 1
• Higher healthcare costs: Screening and treatment programs are expensive without demonstrable benefit. 1, 2

Critical Pitfalls to Avoid

Never perform surveillance urine testing in asymptomatic patients. 1, 2

• Do not order urine cultures on asymptomatic patients with NLUTD, recurrent UTIs, or other chronic conditions. 1
• Positive cultures in asymptomatic patients lead to inappropriate antibiotic prescribing. 1

Do not confuse pyuria with infection. 4

• Pyuria is commonly found in the absence of infection, particularly in older adults with lower urinary tract symptoms such as incontinence. 4
• Positive dipstick or microscopy without symptoms does not warrant treatment. 4

Obtain urine culture BEFORE initiating antibiotics only when symptoms are present. 2

• In symptomatic patients, culture guides appropriate therapy. 1
• In asymptomatic patients, avoid obtaining cultures altogether. 1