C h a p t e r 2 7
Disorders of the Bladder and Lower Urinary Tract
669
may relieve signs and symptoms, and this approach is
used as an adjunct to antimicrobial treatment.
Recurrent lower UTIs are those that recur after treat-
ment. They are due either to bacterial persistence or
reinfection.
38
Bacterial persistence usually is curable
by removal of the infectious source (e.g., urinary cath-
eter or infected bladder stones). Reinfection is man-
aged principally through education regarding pathogen
transmission and prevention measures. Cranberry juice
or blueberry juice has been suggested as a preventive
measure for persons with frequent UTIs. Studies sug-
gest that these juices reduce bacterial adherence to the
epithelial lining of the urinary tract.
42
Because of their
mechanism of action, these juices are used more appro-
priately in prevention rather than treatment of an estab-
lished UTI.
Chronic UTIs are more difficult to treat. Because
they often are associated with obstructive uropathy or
reflux flow of urine, diagnostic tests usually are per-
formed to detect such abnormalities. When possible,
the condition causing the reflux flow or obstruction
is corrected. Most persons with recurrent UTIs are
treated with antimicrobial agents for longer periods
of time in doses sufficient to maintain high urine lev-
els of the drug, and they are examined for obstruction
or other causes of infection. Men in particular should
be investigated for obstructive disorders or a prostatic
focus of infection.
Infections in Special Populations
Urinary tract infections affect persons of all ages. In
infants, they occur more often in boys than in girls.
After the first year of life UTIs occur more often in girls.
Urinary tract infections are more common in women
than men, specifically between 16 and 35 years of
age, at which time women are 40 times more likely to
develop a UTI than age-matched men.
35
This is because
of the shorter length of the female urethra and because
the vaginal vestibule can be easily contaminated with
fecal flora. In men, the longer length of the urethra and
the antibacterial properties of the prostatic fluid provide
some protection from ascending UTIs until approxi-
mately 60 years of age.
43
After this age, prostatic hyper-
plasia becomes more common, and with it may come
obstruction and increased risk for UTI (see Chapter 39).
UrinaryTract Infections in Non-pregnant
Women
Approximately half of all adult women have at least
one UTI during their lifetime.
37
The anterior urethra
usually is colonized with bacteria; urethral massage or
sexual intercourse can force these bacteria back into the
bladder. Using a diaphragm and spermicide enhances
the susceptibility to infection.
35,37
A nonpharmacologic
approach to the treatment of frequent UTIs associated
with sexual intercourse is to increase fluid intake before
intercourse and to void soon after intercourse. This pro-
cedure uses the washout phenomenon to remove bacte-
ria from the bladder.
UrinaryTract Infections in Pregnant
Women
Pregnant women are at increased risk for UTIs. Normal
changes in the functioning of the urinary tract that
occur during pregnancy predispose pregnant women to
UTIs.
44–46
These changes involve the collecting system of
the kidneys and include dilation of the renal calyces, pel-
ves, and ureters that begins during the first trimester and
becomes most pronounced during the third trimester.
Dilation of the upper urinary system is accompanied by
a reduction in the peristaltic activity of the ureters that
is thought to result from the muscle-relaxing effects of
progesterone-like hormones and mechanical obstruction
from the enlarging uterus. In addition to the changes in
the kidneys and ureters, the bladder becomes displaced
from its pelvic position to a more abdominal position,
producing further changes in ureteral position.
The complications of asymptomatic UTIs during preg-
nancy include persistent bacteriuria, acute and chronic
pyelonephritis, and preterm delivery of infants with low
birth weight. Evidence suggests that few women become
bacteriuric during pregnancy. Rather, it appears that
symptomatic UTIs during pregnancy reflect preexist-
ing asymptomatic bacteriuria and that changes occur-
ring during pregnancy simply permit the prior urinary
colonization to progress to symptomatic infection and
invasion of the kidneys. Because bacteriuria may occur
as an asymptomatic condition in pregnant women, it is
recommended that a urine culture be obtained at the
time of their first prenatal visit.
45,46
A repeat culture
should be obtained during the third trimester. Women
with bacteriuria should be followed closely, and infec-
tions should be properly treated to prevent complica-
tions. The choice of antimicrobial agent should address
the common infecting organisms and should be safe for
both the mother and fetus.
UrinaryTract Infections in Children
Acute urinary tract infection is considered to be the
most common serious bacterial infection in childhood,
affecting as many as 8% of girls and 2% of boys dur-
ing the first 7 to 8 years of life.
47,48
In girls, the average
age at first diagnosis is 5 years or younger, with peaks
during infancy and toilet training.
49
In boys, most UTIs
occur during the first year of life and are more common
in uncircumcised than in circumcised boys.
49
Vesicoureteral reflux (VUR), a common childhood
disorder, is believed to predispose to UTI, with both VUR
and UTI being associated with renal scarring and per-
manent kidney damage. Most UTIs that lead to scarring
and diminished kidney growth occur in children younger
than 4 years, especially infants younger than 1 year of
age.
49
The incidence of renal scarring is greatest in chil-
dren with gross VUR or obstruction, in children with
recurrent UTIs, and in those with a delay in treatment.
Childhood UTIs usually are ascending, with inoc-
ulation of feces from the urethra and periurethral
