What is the treatment for a urinary tract infection with leukocytosis (presence of 15+ leukocytes) in urinalysis?

Treatment of UTI with 15+ Leukocytes on Urinalysis

The presence of 15+ leukocytes (pyuria) on urinalysis requires clinical correlation with symptoms before initiating treatment—if the patient has acute urinary symptoms (dysuria, frequency, urgency, fever, or hematuria), start empiric antibiotics immediately and obtain a urine culture; if asymptomatic, do not treat. 1, 2

Diagnostic Confirmation Required Before Treatment

The critical first step is determining whether urinary symptoms are present, as pyuria alone does not justify antibiotic therapy 1:

• Symptomatic patients with pyuria (≥10 WBCs/high-power field or positive leukocyte esterase) AND acute onset of dysuria, frequency, urgency, fever, or gross hematuria should be treated for UTI 1, 2
• Asymptomatic patients with pyuria should NOT be treated, as this represents asymptomatic bacteriuria which does not require antimicrobial therapy 1, 2
• The positive predictive value of pyuria alone for infection is exceedingly low—it often indicates genitourinary inflammation from noninfectious causes 1

Obtain Urine Culture Before Starting Antibiotics

• Collect urine culture via proper technique (catheterization or suprapubic aspiration in infants/young children; midstream clean-catch in cooperative adults) before initiating antimicrobials 3, 1, 2
• Culture results guide definitive therapy adjustments based on susceptibility patterns, typically available within 48-72 hours 2

Empiric Antibiotic Selection for Symptomatic UTI

Uncomplicated Cystitis (Lower UTI)

First-line agents 2, 4:

• Nitrofurantoin 100 mg twice daily for 5 days (preferred first-line due to robust efficacy and antimicrobial stewardship benefits) 2
• Fosfomycin 3 grams as a single dose 2, 4
• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days (only if local resistance <20%) 2, 5

Second-line options 2, 4:

• Fluoroquinolones (ciprofloxacin, levofloxacin) should be reserved for resistant organisms or when other options fail due to resistance concerns 2, 4
• β-lactams such as amoxicillin-clavulanate 4

Pyelonephritis (Upper UTI) or Complicated UTI

Oral therapy for outpatient management 3:

• Ciprofloxacin 500-750 mg twice daily for 7 days (if local fluoroquinolone resistance <10%) 3
• Levofloxacin 750 mg daily for 5 days 3
• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 14 days 3
• Cefpodoxime 200 mg twice daily for 10 days or Ceftibuten 400 mg daily for 10 days 3

Parenteral therapy for hospitalized patients 3:

• Ceftriaxone 1-2 g daily (recommended empirical choice unless multidrug resistance suspected) 3, 2
• Ciprofloxacin 400 mg twice daily IV or Levofloxacin 750 mg daily IV 3
• Cefepime 1-2 g twice daily 3
• Piperacillin-tazobactam 2.5-4.5 g three times daily 3
• Gentamicin 5 mg/kg daily or Amikacin 15 mg/kg daily (with or without ampicillin) 3

Carbapenems and novel broad-spectrum agents (ceftolozane-tazobactam, ceftazidime-avibactam, meropenem-vaborbactam) should be reserved for patients with early culture results indicating multidrug-resistant organisms 3, 4

Pediatric Considerations (2-24 Months)

• Oral antibiotics are as effective as parenteral treatment for most children with UTI 2
• First-line options: Cephalosporins, amoxicillin-clavulanate, or trimethoprim-sulfamethoxazole for 7-14 days 3, 2
• Parenteral therapy reserved for toxic-appearing children, those unable to retain oral intake, or with uncertain compliance 3, 2
• In febrile infants with positive leukocyte esterase, obtain urine culture by catheterization or suprapubic aspiration before initiating antimicrobials 3, 1

Treatment Duration by Clinical Syndrome

• Uncomplicated cystitis in adults: 3-5 days depending on agent 2
• Pyelonephritis in adults: 5-7 days for fluoroquinolones; 7 days for β-lactams 3, 2
• Febrile UTI in children: 7-14 days 3, 2
• Complicated UTI: 7-14 days; 14 days recommended for males where prostatitis cannot be excluded 2

Critical Pitfalls to Avoid

• Do not treat asymptomatic bacteriuria with pyuria—this is a strong recommendation that applies to all populations including elderly, long-term care residents, and catheterized patients 1, 2
• Do not use nitrofurantoin for pyelonephritis or febrile UTIs due to inadequate tissue penetration 2
• Do not use fluoroquinolones as first-line empiric therapy for uncomplicated cystitis—reserve for resistant organisms 2, 4
• Do not treat duration <7 days for febrile/upper UTIs—this is associated with treatment failure 2
• In elderly patients, do not treat based on confusion, delirium, or falls alone without specific urinary symptoms or systemic signs (fever, hemodynamic instability) 1

Adjusting Therapy Based on Culture Results

• Tailor antibiotics based on culture and susceptibility results once available, typically within 48-72 hours 2
• Consider local resistance patterns when selecting empiric therapy, as resistance to trimethoprim-sulfamethoxazole and fluoroquinolones varies significantly by region 2, 4
• For ESBL-producing Enterobacteriaceae causing mild-moderate UTI, alternatives to carbapenems may be used based on susceptibility (nitrofurantoin, fosfomycin, fluoroquinolones if susceptible) 4