Treatment of Significant Bacteriuria
In most patients with asymptomatic bacteriuria (significant bacteriuria without symptoms), antimicrobial treatment should NOT be given, as it provides no clinical benefit and increases antimicrobial resistance and adverse drug events. 1, 2
Key Clinical Distinction: Symptomatic vs. Asymptomatic
The critical first step is determining whether the patient has symptoms or signs of urinary tract infection. Significant bacteriuria alone—even with pyuria—does not warrant treatment in most populations. 1, 2
Populations Where Treatment IS Indicated
Treatment of asymptomatic bacteriuria is recommended in only two specific clinical scenarios where evidence demonstrates reduced morbidity and mortality:
1. Pregnant Women
- Screen all pregnant women with urine culture at least once in early pregnancy 2
- Treat if positive with 3-7 days of antimicrobials 2
- Perform periodic screening for recurrent bacteriuria following therapy 2
- This is the most important exception, as untreated bacteriuria in pregnancy leads to pyelonephritis and adverse pregnancy outcomes 2
2. Patients Undergoing Urologic Procedures with Mucosal Bleeding
- Screen and treat before transurethral resection of the prostate (bacteremia occurs in up to 60% of bacteriuric patients, with sepsis in 6-10%) 3, 2
- Initiate antimicrobials the night before or immediately before the procedure (not 72 hours prior, which increases superinfection risk) 3
- Discontinue immediately after the procedure if no indwelling catheter remains 3
- Continue until catheter removal if an indwelling catheter remains post-procedure 3
Populations Where Treatment IS NOT Recommended
Do not screen or treat asymptomatic bacteriuria in the following populations, as multiple randomized controlled trials show no benefit in preventing symptomatic UTI, complications, or death: 3, 1, 2, 4
- Premenopausal, nonpregnant women 1, 2
- Diabetic women 1, 2
- Elderly persons (community-dwelling or institutionalized)—randomized trials showed similar rates of symptomatic UTI and mortality at 9 years, but significantly more adverse drug events and resistant organisms in treated patients 3, 1
- Spinal cord injury patients—78% had positive cultures but only minimal symptomatic episodes, all responding promptly when treated 3, 1
- Catheterized patients while catheter remains in place 1, 2
- Men (non-elderly, without planned urologic procedures) 5
Special Consideration: Post-Catheter Removal
Asymptomatic women with catheter-acquired bacteriuria persisting 48 hours after catheter removal may be considered for treatment, as one randomized trial showed improved microbiologic and clinical outcomes at 14 days (though reinfecting strains showed increased antimicrobial resistance). 3, 2
Critical Pitfall: Pyuria Does Not Change Management
The presence of pyuria with asymptomatic bacteriuria is NOT an indication for treatment. 1, 2 Pyuria without symptoms does not distinguish asymptomatic bacteriuria from symptomatic UTI and should not trigger antimicrobial therapy. 1
Evidence for Harm from Unnecessary Treatment
A Cochrane systematic review of 1,614 participants demonstrated that antibiotics for asymptomatic bacteriuria showed: 4
- No reduction in symptomatic UTI (RR 1.11,95% CI 0.51-2.43)
- No reduction in complications (RR 0.78,95% CI 0.35-1.74)
- No reduction in death (RR 0.99,95% CI 0.70-1.41)
- Significantly more adverse events (RR 3.77,95% CI 1.40-10.15)
- Increased antimicrobial resistance 4, 6
Clinical Algorithm
- Confirm bacteriuria is truly asymptomatic (no dysuria, frequency, urgency, suprapubic pain, fever, flank pain, altered mental status attributable to UTI)
- Is the patient pregnant? → YES: Treat with 3-7 days of antimicrobials 2
- Is urologic procedure with mucosal bleeding planned? → YES: Treat immediately before procedure 3, 2
- Is this a woman with bacteriuria persisting 48h after short-term catheter removal? → Consider treatment 3, 2
- All other scenarios → Do NOT treat 1, 2, 4