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Identification and treatment of
urinary tract infections (UTIs) is important not only for explaining
and managing signs and symptoms such as fever and dysuria but also
for preventing pyelonephritis and sepsis and long-term complications
including hypertension, chronic renal disease, and renal failure.
Recurrent UTI is often a herald for anatomic and functional abnormalities
that are associated with chronic renal disease.1,2
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Urinary tract infections may involve the urethra and/or
bladder (lower urinary tract) and the ureters, renal pelvis, calyces,
and/or renal parenchyma (upper urinary tract). Lower urinary
tract infection is usually characterized by dysuria, frequency,
urgency, and possibly suprapubic tenderness. The clinical manifestations
of acute pyelonephritis may include fever, lumbar pain and tenderness,
dysuria, urgency, and frequency in association with significant
bacteriuria.
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Recurrence of a urinary tract infection may be caused by a relapse
or a reinfection. A relapse is a recurrence of the infection with
the same infecting microorganism, sometimes as a result of inadequate
therapy. A reinfection is a new infection caused by an organism
that is different from the one responsible for the previous episode.
Specific identification may require serotyping, pyocin typing, phage
typing, antibiotic resistance, or genetic typing of the bacterium
(eg, Escherichia coli), procedures that are not
uniformly available to the clinician. These identification techniques
may also be useful for associating individual incidents with hospital
outbreaks of infection. The term chronic infection is
sometimes used to describe (1) persistence of the urinary tract
infection associated with the same organism for many months or years
or (2) frequent recurrences over many months or years.
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Urinary tract infections involve all age groups from neonates
to geriatric patients. Studies involving routine suprapubic puncture
in more than 1000 infants revealed the presence of bacteriuria in
0.1% to more than 1%3,4. Urinary
tract infection is more common in males, with the majority of these
infections occurring in uncircumcised infants. However, circumcision
to prevent urinary tract infection is not warranted by the low frequency
and usually mild nature of the disease. Premature infants have 2
to 3 times this rate of urinary tract infection. During preschool
years, urinary tract infection is more common in girls (4.5%)
than in boys (0.5%). Long-term surveillance studies of
school children revealed persistent bacteriuria in 1.2% of
girls and in 0.4% of boys. Each year an additional 0.4% of
girls developed bacteriuria.5 Thus the overall
prevalence in school-age girls approached 5%.5-7 These studies
indicated that the peak incidence of urinary tract infection in
children occurred between ages 2 and 6. White girls tended to have more
frequent reinfections than black girls. The incidence of urinary
tract infection in females of high school and college age is approximately
2%.
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Pathophysiology
and Genetics
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Adenovirus types 11 and 21 and the human papovavirus BK have
been reported as causes of acute hemorrhagic cystitis.11-14...