Urinary tract infections occur
when bacteria is present within
the urinary tract in significant
numbers. UTIs are common in
women, with 1 in 5 adult women
aged 20-65 experiencing a UTI at
least once a year. Approximately
50% of women will experience
UTIs at least once in their life.
Cystitis (bladder infection) makes
up the majority of these infections.
Involvement of the upper urinary
tract (pyelonephritis) is less common
compared to that of cystitis but can
be associated with more serious
The onset of UTI can be associated
with one or more of the following
About 25 percent of women with acute cystitis develop recurrent UTIs. Most recurrent infections are from bacteria present in the faecal or periurethral reservoirs. Some strategies can be undertaken to reduce the risk of recurrent infections.
1. Lifestyle changes
2. Prophylactic antibiotics
3. Treatment of any existing
4. Treatment of any vaginal/lower
genital tract infection
In most cases of uncomplicated cystitis
the Escherichia coli is involved. This
bacteria is present in 70-95 percent
of both upper and lower UTIs. Other
common pathogens are Enterococcus
faecalis, Klebsiella species, Proteus
species and yeast.
The largest group of patients with UTIs
is that of adult women. Women are
more prone to UTIs than men because
in females, the urethra is much shorter
and closer to the anus.
Other predisposing factors include:
Rates of UTIs are higher in
postmenopausal women for a few
reasons. For one, the presence of
bladder or uterine prolapse can
cause incomplete bladder emptying
and stasis (reduced or stoppage
flow) of urine which in turn
promotes the growth of pathogens.
Also, the loss of oestrogen after
menopause leads to changes in
the vaginal flora, especially the loss
of lactobacilli, and increases your
susceptibility to infection.
2. Sexual activity
UTIs are very common in women
aged 18-30 years as it is associated
with coitus (the so-called
‘honeymoon cystitis’). In this age
group, sexual intercourse is the
cause of 75 to 90 percent of bladder
infections, with the risk of infection
being related to the frequency of
sex. The use of spermicides and
diaphgrams for contraceptive
purposes further increases the risk
of UTIs as it causes a change in the
vaginal flora and eradication of the
3. Recent instrumentation of the
urinary tract (e.g. catheterisation,
cystoscopy, urodynamic studies)
The insertion of foreign instruments
into the urinary tract promotes the
translocation of bacteria colonised
around the peri-urethral area into
the bladder and other parts of the
urinary tract. This increases the risk
of developing bacteruria (presence
of bacteria in the urine) in significant
numbers eventually leading to a UTI.
4. Foreign bodies (e.g. catheters,
Urinary catheters are the most
important risk factors for bacteriuria.
Catheters introduce organisms
into the bladder and promote
colonisation by providing a foreign
surface for bacteria to adhere to
and by causing irritation of the
bladder mucosa. 80 percent of UTIs
that occur while in hospitals or
healthcare institutions are related
to urethral catheterisation, and 5-10
percent are related to manipulation
of the genito-urinary tract. Urinary
stones similarly irritate the bladder
as well as provide a nidus for bacteria
to adhere to, thereby increasing the
risk of developing a UTI.
5. Neurological disorders, drugs or
pelvic organ prolapse
These conditions may cause
incomplete emptying of the bladder,
thereby promoting stasis of urine
which increases the risk of UTI
6. Medical conditions (e.g. diabetes)
Diabetes leading to glycosuria
(sugar in the urine) makes for fertile
breeding ground for bacteria. A
study showed that 9.4 percent of
patients with Type 2 diabetes had a
UTI compared to only 5.7 percent of
people without diabetes.
The diagnosis of a UTI can be
suspected from a well-taken history
and physical examination.
Specific tests to confirm a UTI include
a urine dipstick, urine analysis and
urine culture. The main emphasis lies
with the detection of pyuria (white
blood cells or pus cells in the urine) on
dipstick and urine analysis. Associated
findings can include microscopic
haematuria (blood in the urine which
cannot be detected by the naked
eye). A urine culture will help in the
identification of the organism causing
No imaging studies are indicated
in the routine evaluation of an
Empirical antibiotics are usually
prescribed for UTIs. The patient may be
prescribed alternative antibiotics after
the urine culture results are available.
The duration of treatment of the UTI
depends on the antibiotic in use. Some
common first-choice agents for the
treatment of uncomplicated cystitis in
women include nitrofuratoin, bactrim
or beta-lactams such as cephalexins.
Most patients can be treated on an
outpatient basis. However, hospital
admission for management of
complicated UTIs may be indicated
in some patients. Complicating
factors include the presence of
structural abnormalities (e.g. stones,
indwelling catheters), metabolic
disease (e.g. diabetes, pre-existing
kidney disease) or patients who are
immunosuppressed and therefore
more prone to serious infections (e.g.
HIV, patients on chemotherapy).
Recurrent UTI is defined as having
UTI three or more times in a year.
This can be due to the same or
different bacteria. In these cases,
further investigations may need
to be done, e.g. renal ultrasound,
intravenous pyelogram, cystoscopy,
urine for tuberculosis and cytology,
to look for any underlying causes and
complications of recurrent UTIs.
Patients with recurrent UTI may be
given prophylactic antibiotics for a
period of six months. They will also
be advised on the various preventive
measures and the importance of
keeping good personal hygiene.
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