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)
- 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
- Congenital abnormality or distortion of urinary
- Indwelling catheter
- Prostatic hypertrophy
- 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
- Complicated UTIs caused by variety of organisms generally
- Acquired via 3 possible pathways:
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
- 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,
- 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
- Voiding after intercourse may help prevent recurrent infections
- Limit length of time of catheterization.
- Underlying structural abnormalities of urinary tract
- Obstruction from
- Poor bladder emptying resulting in residual urine volumes.
- Prostatic hypertrophy
- 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
- Lower UTI:
- Suprapubic heaviness
- Gross hematuria
- Upper UTI:
- Flank pain
Means of Confirmation
- Ability to demonstrate significant numbers of microorganisms
present in appropriate urine specimen to distinguish contamination
- Microscopic examination of urine
- Pyuria (signifies inflammation and not necessarily ...