Urinary tract infections are common presentations to the family physician's office. It is important to delineate which UTIs are complicated, require further investigations, and management.

History Edit

  • Cystitis: dysuria, urgency, frequency, suprapubic pain/tenderness, new onset confusion
  • Urethritis: similar symptoms to cystitis - urethral d/c may be present
  • Pyelonephritis: cystitis symptoms, + systemic manifestations - fever, rigors, change in mental status, flank pain, costovertebral tenderness, hematuria, pelvic discomfort, N/V
  • Renal abscess: pyelo symptoms that persist despite abx
  • Past medical history: prior history of UTI, catheter, renal anomalies, immunosupression, history of incontinence, spinal cord injury, neuromuscular disorders, diabetes, renal stones
  • Medications: recent abx use
  • Allergies
  • Social history - including sexual history as STIs can present with similar Sx
  • Review of systems: vaginal symptoms, BMs
  • In a child < 3 years old with fever but no apparent source - suspect UTI
  • In elderly patients/young patients with non-specific complaints e.g. abdominal pain, fever, delirium, irritability, urinary retention, incontinence always consider UTI as part of the differential

Risk factors Edit

  • female, frequent sexual intercourse, catheter use, vesi-ureter reflux, posterior urethral valves, neurogenic bladder (e.g. spinal cord injury), diabetes mellitus, immunosuppresion , gyne prolapse, estrogen deficiency, benign prostate hyperplasia

Common pathogens Edit


  1. Klebsiella
  2. E.coli
  3. Enterococci
  4. Proteus, pseudomonas
  5. Staph saprophyticus


  1. Candida - common colonizer or urinary tract in hospitalized patients. Often does not require treatment
  2. Staph aureus - always do blood cultures as uncommon in absence of catheter/instrumentation --> consider hematogenous spread
  3. Urethritis: chlamydia, gonorrhea, trichomonas, HSV, ureaplasma, mycoplasma genitalium
  4. Coagulase -negative staphylococcus (other than staph saprophyticus) rarely cause UTIs and generally do not require treatment

Physical Edit

  • Vitals
  • General
  • Abdominal exam - CVA tenderness, DRE (if thinking prostatitis)
  • +/- pelvic exam

Investigations Edit

  • NOT suggestive of UTI: foul smelling, cloudy urine, change in color, + urine dip without symptoms of UTI, pyuria/bacteriuria without signs/symptoms of UTI
  • Urinalysis and microscopy can rule OUT a UTI. Not rule in. Leuks - inflammation, Nitrites - presence of certain bacteria (not necessarily an infection).
    • Nitrites can be falsely negative if frequent bladder emptying 
    • Nitrates negative in gram positive bug
  • If uncomplicated risk of UTI--> do scoring system
    • 1 point for each - dysuria, leuks +, nitrites +
    • 0-1 point --> send for culture
    • 2-3 points--> start empiric therapy without waiting for culture
  • Investigations:
    • Blood pressure
    • Urinalysis
    • Urine culture - clean catch, not toilet trained: urethral catheterization (NO urine bags)
      • Sterile pyuria- can indicate urethritis, STI, nephritis, foreign body
    • Cr, EGFR (if required for abx dosing, assess for acute kidney injury)
    • Blood culture - complicated UTI or toxic appearing
    • Chlaymdia/gonorrhea testing (see STI) if high risk
    • Screen for asymptomatic bacteruia in all pregnant women and those undergoing urologic surgery
    • Renal ultrasound +/- Voiding cystourethrogram
      • Renal ultrasound: hydronephrosis, renal abscess, anatomic anomalies
      • Voiding cystourethrogram: reflux (grading system - need for UTI prophlaxis and referral)
        • First UTI in male 
        • First UTI in female < 3 years old or second UTI in female >3 years old
        • Complicated pyelonephritis
        • Family history of renal anomalies/recurrent UTIs esp. with HTN or poor growth
        • Recurrent UTI
    • CT renal: if no improvement in symptoms in 72 hours and want to r/o abscess, r/o struvite stone



  • Two uncomplicated UTIs within 6 months OR 3+ urine cultures within 12 months


  • Occurs within 2 weeks of completing Abx (different organism)


  • Occurs within 2 weeks of completing Abx (original organism)

Uncomplicated cystitisEdit

  • cystitis in non-pregnant, non-immunocompromised host, without underlying structural/neurological d/o

Complicated cystitisEdit

  • structural/functional abnormalieis of renal system: obstruction (stones), catheter, spinal cord injury, neurogenic bladder, polycystic kidney disease
  • UTI in men
  • Pregnancy
  • Diabetes mellitus, immunosuprresion
  • Neonate

Treatment Edit

  • Treatment should only be considered if 1) signs and symptoms of UTI and 2) leuk esterase or WBC in urine +/- nitrates
  • Always consider local resistance patterns and patient's recent ABx use when prescribing
  • Aminoglycosides, cephalosporins, fluroquinolones and trimethoprim-sulfamethaxazole DO NOT COVER enterococcus
  • Ciprofloxacin and TMP-SMX do not reliably cover e.coli

Asymptomatic bacteriuriaEdit

  • NO treatment even in catheter patients
  • Exception: pregnant women, about to undergo urologic surgery

Non-neuropenia Adult Patients without systemic signs/symptoms (no catheter)Edit

  • Order urine R+M, C+S
  • Antibiotic options (tailor to culture susceptability)
    • Amox/clavulin 500mg PO TID or 875 mg PO q12 hours
    • Cephalexin 500mg PO q6 hours
    • Nitrofurantoin (Macrobid) 100mg PO BID
    • TMP-SMX 1 DS tab PO q12 hours
    • Ciprofloaxin 500mg PO q12 hours (reserve for severe or pseudomonal coverage)
    • Fosfomycin 3 grams dissolved in 1/2 cup water Po x 1 dose
  • Duration of therapy:
    • Risk factors (male, neurogenic bladder, immunosuppressive therapy, GU structural abnormalitiy e.g. non-obsturcting stone) --> Male 7 days, Other: 5-7 days for fluroquinolone, TMP/SMX, nitrofurantoin or 7-10 days with beta-lactam. Note some patients may require longer treatment
    • No risk factors: 3 days (fluroquinolone or TMP/SMX), 5-7 days (nitrofurantoin), 7 days (beta-lactam)
  • Adjustments: require renal adjustments. Do not rx nitrofurantoin if CrCl <60ml/minute

Non-neutropenic Adult Patients with systemic signs/symptoms (no catheter)Edit

  • Order blood cultures x 2, Urine R+M, C+S. 
  • Antibiotic options
    • CiprofloxacinPO/IV q 12 hours
    • IV gentamycin 3mg/kg IV q 24 hours (tobra/amikacin) + ampicillin 1 gram IV q 6 hours
    • If CrCl < 40 ml/min or age >75 ceftraixone 1 gram IV q 24hours
    • If risk factors for pseudomonas: tobramycin 3mg/kg IV q24 hours or ceftazadine 1-2gram IV q8 hours or cipro
  • Duration of therapy:
    • Female: fluroquinolone (7 days), other (10-14 days)
    • Male: 10-14 days
  • Switch to PO: hemodynamicallys table, clinically improving, able to tolerate PO, functioning GI tract

Catheter related UTIEdit

  • Symptoms of rigors, delirium, new CVA tenderness, fever (cannot rely on dysuria, urgency, frequency)
    • None of the above--> no investigations, no treatment, look for alternative etiology, remove catheter if possible
    • Yes--> remove/change catheter, send urine R+M, C+S
  • If mild-moderate: (use different abx class than that used in last 3 months)
    • amoxicillin/clavulanic acid
    • Trimethoprim/sulfamethoxazole
  • If severe (draw blood cultures)
    • PO/IV cipro
    • IV gentamycin + ampicillin
    • If CrCl <40 or age > 75: ceftriaxone 1 gram IV q 24
    • If suspect pseudomonas: tobramycin 3mg/kg IV q24 hours or ceftazadine 1-2gram IV q8 hours or cipro
    • Duration: 7 days if prompt response, 10 days if delayed
  • Tailor antibiotics to susceptability results. Switch from IV to PO when hemodynamically stable, improving clinically, able to tolerate PO, normal functioning GI tract

Special Population TreatmentEdit

Asymptomatic Bacterirua in PregnancyEdit

  • Screen at first prenatal visit.
  • Amoxicillin 500mg PO TID x 3-7 days. Other options: nitrofurantoin, TMP/SMX as long as no contraindications.
  • Nitrofurantoin contraindicated in term pregnant woman (>36 weeks), labor, neonates due to risk of hemolytic anemia
  • TMP/SMX is contraindicated in first trimester- risk of folate deficiency/NTD, and during last 6 weeks of pregnancy due to risk of kernicterus
  • Perform follow-up culture and retreat if necessary 

Acute Cystitis in PregnancyEdit

  • Do follow-up culture to ensure resolution
  • Cephalexin 500mg PO TID-QID x 7 days
  • Other options: amoxicillin x 7days, nitrofurantoin x 5 days, fosfomycin x 1 dose , TMP/SMX x 3 days as long as no contraindications

Pyelonephritis in PregnancyEdit

  • Ceftriaxone IV

Early Recurrence <1 month:Edit

  • re-treat x 7-14 days. Repeat culture. 
  • Options: TMP/SMX, nitrofurantoin 


  • 2 or more episodes in 6 months or > 3 episodes/year
  • First line:
    • TMP/SMX 1 tab or 1/2DS tab qhs 3x weekly or post-coital
    • Trimethoprim 100mg PO qhs or post-coital
    • Nitrofurantoin 50mg or 100mg qhs or post-coital
  • Second line:
    • Cephalexin 125-250mg qhs or post-coital
    • Norfloxacin 200mg PO every other day or 3x per week or post-coital
    • Fosfomycin 3 grams dissolved in 1/2 cup cold water q 10days


First line

  • TMP/SMX 5-10mg/kg/day divided q12 hours
  • Nitrofurantoin 5-7mg/kg/day divided q6hours (DO NOT USE IN < 1 month old)

Second line

  • Amoxicillin 40mg/kg/day divided q8 hours (high rate of resistance therefore need longer course)
  • Cephalexin 25-50mg/kg/day divided q6hours

Third line

  • Cefixime 8mg/kg/day divided q12-24 hours
  • Amox/clav 40mg/kg/day divided BID

Inpatient: IV amp/gent or ceftriaxone/cefotaxime 

  • <2 months 5-7 days of IV treatment then PO x total 10-14
  • PO cefixime 
  • Fluroquinolones are contraindicated in children < 12 years of age

Prevention Edit

  • Regular voiding patterns
  • Good hygiene practices
  • Remove catheter whenever it is contraindicated
  • Proper catheter maintenance practice (e.g. sterile insertion)


  • sepsis
  • pyelonephritis
  • impacted infected stones
  • acute kidney injury

Differential Edit

  • See dysuria page
  • STIs, vaginitis, renal stones, interstitial cystitis, prostatitis


TOH guidelines for treatment of UTI

Anti-infective Guidelines for Community Acquired Infections 2013