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Source: Coyle EA, Prince RA. Urinary Tract Infections and Prostatitis. In: DiPiro, JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM. Pharmacotherapy: A Pathophysiologic Approach. 8th ed. http://accesspharmacy.com/content.aspx?aid=8004270. Accessed July 26, 2012.

  • Presence of microorganisms in urine that cannot be accounted for by contamination.
    • Lower tract infections include:
      • Cystitis (bladder)
      • Urethritis (urethra)
      • Prostatitis (prostate gland)
      • Epididymitis
    • Upper tract infections involve kidney and referred to as pyelonephritis.
    • Uncomplicated urinary tract infections (UTIs) not associated with structural or neurologic abnormalities.
    • Complicated UTIs result of predisposing lesion of urinary tract:
      • Congenital abnormality or distortion of urinary tract
      • Stone
      • Indwelling catheter
      • Prostatic hypertrophy
      • Obstruction
      • Neurologic deficit
    • Recurrent UTIs: ≥3 UTIs occurring within 1 year.
      • Characterized by multiple symptomatic episodes with asymptomatic periods in between.
      • Due to reinfection with different organism or relapse caused by same initial organism.
    • Asymptomatic bacteriuria: significant bacteriuria (>105 bacteria/mL of urine) in absence of symptoms
      • Common in persons 65 years of age and older
    • Symptomatic abacteriuria: symptoms of frequency and dysuria in absence of significant bacteriuria.
      • Commonly associated with Chlamydia infections.

  • Usually caused by single bacterial organism that originates from bowel flora of host.
    • Uncomplicated UTIs most commonly caused by Escherichia coli.
    • Complicated UTIs caused by variety of organisms generally more resistant.

  • Acquired via 3 possible pathways:
    • Ascending
      • Primary UTI acquisition route in females
        • Urethra colonized from perirectal area, which then enters bladder and can ascend ureters to kidney
    • Hematogenous (descending)
      • Result of dissemination of organisms from distant primary infection.
      • Uncommon
    • Lymphatic
      • Insignificant role
  • Development of infection depends on:
    • Size of inoculum
    • Virulence of microorganism
      • Bacteria adhere to urinary epithelial cells by fimbriae, resulting in colonization of urinary tract, bladder infections, and pyelonephritis.
      • Additional virulence factors: hemolysin and aerobactin.
    • Host defense mechanisms
      • Normal urinary tract resistant to invasion by bacteria and efficient in rapidly eliminating microorganisms that reach bladder.

  • Prevalence of UTIs varies with age and gender.
    • Overall incidence increases substantially in persons older than 65 years, with majority of infections being asymptomatic.
    • More common in females because of anatomic differences in location and length of urethra, which supports ascending route of infection.

  • Voiding after intercourse may help prevent recurrent infections in women.
  • Limit length of time of catheterization.

  • Age
  • Underlying structural abnormalities of urinary tract
    • Obstruction from bladder hypertrophy
  • Poor bladder emptying resulting in residual urine volumes.
    • Prostatic hypertrophy
    • Tumors
    • Anticholinergic drugs
    • Neuromuscular disease (including strokes)
  • Resident of nursing home
  • Frequent hospitalizations
  • Fecal incontinence
  • Urinary catheterization

  • Elderly patients frequently do not experience specific urinary symptoms, but will present with:
    • Altered mental status
    • Change in eating habits
    • Gastrointestional (GI) symptoms

Signs and Symptoms

  • Lower UTI:
    • Dysuria
    • Urgency
    • Frequency
    • Nocturia
    • Suprapubic heaviness
    • Gross hematuria
  • Upper UTI:
    • Flank pain
    • Fever
    • Nausea
    • Vomiting
    • Malaise

Means of Confirmation and Diagnosis

  • Ability to demonstrate significant numbers of microorganisms present in appropriate urine specimen to distinguish contamination from infection.

Laboratory Tests

  • Urinalysis
  • Microscopic examination of urine
    • Bacteriuria (Table 1)
    • Pyuria (signifies inflammation and not necessarily ...

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