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A. Characteristicsnavigator

  1. Acute lower tract infection is also called acute bacterial cystitis
  2. Upper tract infection is pyelonephritis ("pus" causing kidney inflammation)
  3. Symptoms of Acute UTI
    1. Dysuria - pain on urination
    2. Urinary Frequency (polyuria), urgency
    3. Hematuria
    4. Fevers, nausea and/or vomiting suggest pyelonephritis
    5. Symptoms of UTI are blunted in very young, very old, immunocompromised
  4. UTI's are much more frequent in women
    1. Usually associated with recent sexual activity and particularly to use of diaphragm
    2. Likely due to shorter urethra and closer proximity of urethra to anus in women versus men
    3. History of >1 UTI is also major risk factor for recurrent UTI
    4. Majority of UTIs are due to enteric organisms and Staphylococcus saprophyticus
    5. Recurrent UTIs in women using diaphragm should prompt contraception change
    6. Cystitis may be asymptomatic, particularly in elderly women
    7. Antibiotic prophylaxis for recurrent UTIs in children did not reduce recurrence but had
  5. 5X increased antibacterial resistance [20]
  6. Vesicoureteric Reflux (VUR) [2]
    1. Present in 1-2% of children, often inherited in autosomal dominant manner
    2. Common cause for recurrent UTIs in infants and children
    3. VUR with chronic UTIs can lead to renal damage, hypertension, chronic renal failure
    4. Unclear if detection of children with VUR will prevent recurrent UTI and renal dysfunction
    5. Chronic suppressive antibiotics ± surgery are used
    6. Surgery provides only mild benefit beyond antibiotics alone in most patients
  7. Spread of Infection
    1. Retrograde Ascending Infection (most common) - pyelonephritis
    2. Pyelonephritis is pyuria, fever, and flank pain; bacteremia is common
    3. Hematogenous (uncommon; bacteremic and immunocompromised patients)
  8. Interstitial cystitis is a non-infectious disease with unclear etiology (see below)
  9. Foley (bladder) catheter related infections are common (see below)

B. Organisms navigator

  1. Gram Negative Enteric organisms usually causative agents
    1. Escherichia coli is by far the most common
    2. Proteus mirabilis
    3. Klebsiella pneumoniae
  2. Other Common Organisms
    1. Enterococci
    2. Staphylococcus saprophyticus (coagulase negative, G+ organism)
    3. In many outpatient settings, Staph saprophyticus is second most common cause of UTI
  3. Urea Splitting Organisms
    1. If urine pH >7.9 suggests a urea splitting organism
    2. This is because the kidney cannot alkalinize urine to pH >8
    3. Major urea splitting organism: Proteus mirabilis (some Klebsiella, Serratia)
    4. Patients can develop "Staghorn Calculi" from recurrent infections
    5. E. coli does not have urease
  4. Other - may be suggested by culture negative UTI
    1. Urethritis: C. trachomatis, N. gonorrhoea, Ureaplasma urealyticum, Herpes Simplex Virus
    2. Vaginitis: Candida species, Trichomonas vaginalis
    3. Tuberculosis
  5. Staphylococcus aureus
    1. Presence in the urine is usually due to hematogenous spread
    2. Should consider search for hematogeneous source such as endocarditis
  6. Candida ssp.
    1. Increasing cause of UTI's in hospitalized patients, usually Candida albicans
    2. Main risk factors: broad spectrum antibacterial therapy, urinary catheterization
    3. Occasionally, non-albicans Candida (such as C. tropicalis, C. glabrata) may be cultured
  7. Stenotrophomonas (Xanthomonas) maltophilia
    1. Increasing cause of UTI's in hospitalized patients
    2. No cases of asymptomatic bacteriuria with this organism
    3. Double gram negative antibiotic coverage often recommended

C. Diagnosisnavigator

  1. Clinical Diagnosis and UTI Probability [1,3]
    1. 1 or more symptom makes likelihood of UTI ~50% in women
    2. Dysuria and frequency without vaginal discharge or irritation makes UTI ~90% likely
    3. Dipstick urinalysis in women with 1 or more symptoms cannot completely rule out UTI
    4. In women with previous UTI, recurrent symptoms makes probability of UTI ~90%
    5. Symptoms of vaginitis such as vaginal irritation or discharge reduce likelihood of UTI
  2. Fever
    1. Should generally not be present in uncomplicated UTI
    2. May signify pyelonephritis
    3. May also signify bacteremia
    4. Note chills, rigors, pulse rate to help assess for bacteremia
  3. Bactiuria
    1. Asymptomatic bactiuria is found in 5-6% of sexually active young women [6]
    2. Asymptomatic bactiuria associated with use of sexual activity and diaphragm+spermacide
    3. Bacteriuria without pyuria (that is, white blood cells in urine) is not UTI
    4. Asymptomatic bactiuria progressed to UTI within 1 week in 8% of women [6]
    5. Bacteriuria alone should not be treated unless patient is pregnant or at high risk
  4. In general, urinary dipstick and microscopic exam are sufficient for diagnosis
    1. Bacteria in urine
    2. Presence of white blood cells
    3. Low grade hematuria is frequently present
    4. Dipstick may be falsely negative
  5. In complicated patients, urinary culture, gram stain, +/- blood cultures should be done
  6. Evaluation for Focus of Infection
    1. Initial or infrequent uncomplicated UTI does not require further evaluation
    2. Frequent UTI in Female or recurrent UTI in female with risk factors should be evaluated
    3. Second UTI in Male deserves an evaluation for focus
    4. Abdominal radiograph to assess for kidney stone
    5. Intravenous pyelogram or retrograde pyelogram
    6. Ultrasound
    7. Cystoscopy
  7. UTI in Infants [14]
    1. Risk factors for UTI being present in infants with fever include:
    2. History of previous UTI: likelihood ratio (LR) ~2.5X
    3. Temperature >40°C: LR ~3.2X
    4. Suprapubic tenderness: LR 4.4X
    5. Lack of circumcision: LR of UTI ~2.8X
    6. Presnece of circumcision: LR of UTI 0.33X
    7. Combinations of findings more useful than individidual ones
    8. In verbal children, abdominal pain (LR 6.3), back pain (LR 3.6), dysuria/frequency (LR 2.5) and new onset urinary incontinence (LR 4.6) increased risk of UTI

D. Complicationsnavigator

  1. Ascending infection can lead to stricture with hydronephrosis and renal failure
  2. Pyelonephritis [7]
    1. Clinical diagnosis: flank pain, nausea and vomiting, dehydration, fever >102° F
    2. Laboratory: WBC casts in urine (pyuria, leukorrhea)
    3. Over 250,000 cases per year, with 100,000 hospitalizations
    4. Most patients with severe systemic signs and UTI have pyelonephritis ± bacteremia
    5. High fevers may persist for >48 hours in patients with pure pyelonephritis
    6. Persistence of fever for >72 hours should prompt evaluation for further complications
    7. Strongly consider obtaining blood cultures along with standard labs in these patients
  3. Emphysematous Pyelonephritis [4,5]
    1. This condition is an emergency requiring surgical or other interventional treatment
    2. Over 90% of these infections occur in diabetics
    3. Papillary necrosis complicates ~20% of cases
    4. E. coli is most common (50-75% of cases) but gas forming organisms also common
    5. Other gram negative rods cause the majority of the remaining cases
    6. May present with pneumaturia (air in urine), fever, anorexia, rigors, asthenia [5]
    7. Diagnosis made by CT scan showing gas in kidney tissue
    8. Vigorous hydration, IV antibiotics, and control of hyperglycemia
    9. Radical nephrectomy was the standard of care
    10. Radiographically guided percutaneous drainage may be successful in localized infections
    11. Surgery with total nephrectomy for patients who do not improve
  4. Perinephric Abscess - urgent surgical evaluation required
  5. Renal stones (especially from urea splitter)

E. Therapy [1,10]navigator

  1. Uncomplicated UTI, Female
    1. Three days course usually adequate for younger women with uncomplicated infection
    2. Single doses of fosfomycin or gatifloxicin (Tequin®) are often sufficient [1]
    3. Standard: TMP/SMX (Bactrim®, Septra®) - 1 DS tablet po bid x 3 days (least expensive)
    4. Resistance to TMP/SMX is 10-20% in some places, particularly with previous use [8]
    5. Second Line (sulfa allergy or resistance): fluoroquinolone (usually 3 days)
    6. Ciprofloxacin is superior to amoxicillin-clavulanate (Augmentin®) x 3 days for acute UTI [9]
    7. Alternate second line: single 3gm dose of fosfomycin (Monurol®) [11]
    8. Nitrofurantoin or fluoroquinolone effective in most TMP/SMX resistant isolates [9]
    9. Nitrofurantoin monohydrate (Macrodantin®)100mg po bid x 7 days has low resistance
    10. Oral second generation cephalosporin can be used (less effective than TMP/SMX)
    11. Amoxicillin-clavulanate (Augmentin®) or possibly amoxillin alone are also effective
  2. Urinary Analgesia
    1. Adding urologic analgesic
    2. Phenazopyridine (Pyridium®) 100-200mg po tid prn for 2-3 days is usally used
    3. Warn patient that phenazopyridine causes orange urine (may be mistaken for blood)
  3. Patient Initiated Treatment
    1. Patient initiated treatment for uncomplicated UTI in women with history of UTI using ofloxacin or levofloxacin is very effective and safe [13]
    2. Use of TMP/SMX in appropriate patients is very cost effective
    3. Single dose gatifloxacin 400mg po or fosfomycin 3gm is alternative
  4. Higher Risk
    1. Diabetes or Symptoms >7 days or age >65 years old or nursing home patient
    2. In general, at least 7 days of antibiotics are recommended
    3. Fluoroquinolones are preferred - ciprofloxacin, levofloxacin, gatifloxacin, lomefloxacin
    4. TMP/SMX (Bactrim®, Septra®) - caution sulfa allergies, less effective than quinolones
    5. Oral third generation cephalosporin or Augmentin® may also be used
  5. Post-Coital Regimen
    1. Not for use with definitive pregnancy
    2. Post-coital treatments with TMP/SMX single strength or nitrofurantoin single dose
    3. Alternative: ciprofloxacin 250mg, levofloxain 250mg, gatifloxacin 400mg singe dose
  6. Pregnancy
    1. Consider 7 day course; also treat asymptomatic bacteriuria
    2. Amoxicillin is generally not recommended
    3. Nitrofurantoin (Macrodantin®) - 7 days usually required
    4. Cephalosporin - third generation oral agents may be effective (such as cefixime, cepifime)
  7. Complicated / Multiple UTIs
    1. All male patients with UTI are considered to have complicated infections
    2. Pyelonephritis defined by fever, flank pain, pyuria ± WBC casts
    3. Parenteral therapy is usually preferred: gentamicin and/or ampicillin or vancomycin
    4. Oral: Ciprofloxacin or other fluoroquinolone (except norfloxacin) for 7-14 days
    5. For uncomplicated pyelonephritis in normal patients, 7 days of ciprofloxacin (Cipro®) is superior to 14 days of TMP/SMX DS (Bactrim®) [7]
    6. At least one dose gentamicin IV (or an intravenous fluoroquinolone) should be given to most patients with complicated UTI
    7. If patient fails to respond to therapy, consider resistant organism, perinephric abscess (check ultrasound), or a second infection
    8. Catheters should generally be removed, or silver allow catheters used [15]
    9. Antibacterial coated catheters prevent bactiuria in hospitalized patients catherized for the short-term [16]
  8. Urosepsis
    1. Gram stain of urine may be used initially to guide therapy (pending culture results)
    2. However, if patient is suspected of being septic, broad spectrum coverage recommended
    3. Timentin® OR Zosyn® with an aminoglycoside should be used initially
    4. Ceftriaxone, ceftazidime, imipenem, meropenem, or fluoroquinolone may be used instead of Timentin® or Zosyn®
    5. All patients with urosepsis should receive at least one dose of aminoglycoside
    6. However, avoid >2 doses of aminoglycosides in elderly or in renal insufficiency
    7. Consider vancomycin if resistant enterococcus (or staphylococcus) is likely
    8. Rifampin may be added for staphylococcal or resistant pneumococcal infections
    9. Oral ciprofloxacin as effective as IV in severe and complicated UTIs/pyelonephritis
    10. If Pseudomonas is suspected, use anti-pseudomonal penicillin or ceftazidime or penem
  9. Candidal UTI
    1. Majority are caused by C. albicans
    2. Oral fluconazole (200mg po qd) may be effective but resistance increasing
    3. Amphotericin bladder washes can also be used, usually 5 days
    4. Many non-albicans candida including C. tropicalis are resistant to fluconazole
  10. Culture Negative UTI
    1. Main causes are likely Chlamydia trachomatis and Ureaplasma urealyticum
    2. Both organisms are sensitive to doxycycline, 200mg po bid x 7-10 days
    3. Second generation macrolides (clarithromycin, azithromycin) may also be used
  11. Foley-Catheter Associated UTI
    1. In long term catheterization, treatment not indicated or effective unless patient has signs or symptoms of upper genitourinary tract infection
    2. Successful therapy usually requires removal of catheter
    3. Intermittent straight catheterization (QID) preferable to indwelling Foley catheter
    4. Catheters should be removed as soon as possible in general because 100% will eventually become infected
    5. Silver alloy catheters (not silver oxide) reduce UTI risk ~80% [15]
    6. Antimicrobial impregnated cathters reduce bactiuria in hospitalizated patients [16]

F. Preventionnavigator

  1. Good Hygiene
    1. Including urinating after sexual activities
    2. Generous fluid intake
    3. After defecation, wipe front to back
  2. Discontinue use of diaphragm with spermicide
  3. Cranberry Juice
    1. Appears to reduce incidence of bacteriuria and pyuria
    2. Active ingredient apparently not related to urinary acidification
  4. Chronic suppressive antibiotics therapy is last resort [1]
    1. Probably better to use antibiotic therapy intermittently
    2. TMP/SMX (Bactrim®) SS 1 po 3 times weekly or nitrofurantoin 50-100mg po qd
    3. Ciprofloxacin should generally be reserved for treatment of symptomatic pyuria
    4. Asymptomatic bactiruia in diabetic women should not be treated with antibiotics [17]
  5. In suitable patients, self-treatment at onset of symptoms may be appropriate
  6. Surgical treatment of bilateral VUR in children <12 years does not appear to lead to improved renal functional outcomes [18]
  7. Antibiotic Coated Urinary Catheters
    1. Silver alloy catheters (not silver oxide) reduce UTI risk ~80% [15]
    2. Candidal UTI's increased in catheterized patients; reduced ith nitrofurazone-impregnated catheters [21]
  8. Chronic suppressive antibiotic therapy for VUR patients is mainstay [2]

G. Chronic Interstitial Cystitisnavigator

  1. Chronic progressive disorder of unknown etiology
  2. More common in women than men
  3. Symptoms
    1. Urinary urgency and frequency
    2. Pelvic Pain
    3. Reduced bladder capacity in some cases
  4. Erosions and, in ~10% of cases, frank ulcerations, may be seen on cystoscopy
  5. Treatment
    1. Invasive
    2. Medical
    3. Surgical
  6. Invasive
    1. Hydrodistention under anesthesia
    2. Intravesicular administration of dimethyl sulfoxide (DMSO)
  7. Medical [19]
    1. Hydroxizine (Atarax®) - 10-25mg po qd-tid
    2. Amitriptyline (Elavil®) - 10-50mg po qd-bid
    3. Pentosan (Elmiron®) - 100mg po tid
    4. Leukotriene inhibitors (such as montelukast) may be effective and very well tolerated
    5. Some relief in 30-50% of patients with pelvic pain (placebo rates ~18%)
  8. Surgical
    1. Laser therapy
    2. Reconstructive surgery
    3. Total cystectomy

H. Eosinophilic Cystitis [12] navigator

  1. Very rare disorder, <70 cases reported
  2. Mass (tumor-like) lesions of bladder
  3. Lesions composed of prominant infiltrates of eosinophils
  4. If tissue eosinophilia is present, true eosinophilic cystitis is not the cause
    1. Transurethral resections, other trauma lead to local bladder and systemic eosinophilia
    2. Prostate surgery also associated with local and systemic eosinophilia
  5. Causative agents have not been defined
  6. Physical Examination
    1. Mobile suprapubic mass
    2. Edema
  7. Cystocscopy: plaques, ulceration, polypoid or bullous edema
  8. Radiologic evaluations suggest tumor mass
  9. No convincing association with allergies

Resources navigator

calcAbsolute Neutrophil Count

References navigator

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  11. Fosfomycin. 1997. Med Let. 39(1004):66
  12. Atala A and Misdraji J. 1998. NEJM. 339(9):616 (Case Record)
  13. Gupta K, Hooton TM, Roberts PL, Stamm WE. 2001. Ann Intern Med. 135(1):9 abstract
  14. Shaikh N, Morone NE, Lopez J, et al. 2007. JAMA. 298(24):2895 abstract
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  16. Johnson JR, Kuskowski MA, Wilt TJ. 2006. Ann Intern Med. 144(2):116 abstract
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  18. Smellie JM, Barratt TM, Chantler C, et al. 2001. Lancet. 357(9265):1329 abstract
  19. Pentosan. 1997. Med Let. 39(1002):56 abstract
  20. Conway PH, Cnaan A, Zaoutis T, et al. 2007. JAMA. 298(2):179 abstract
  21. Stensballe J, Tvede M, Looms D, et al. 2007. Ann Intern Med. 147(5):285 abstract