What is a urine infection?
A urine infection is caused by bacteria (germs) that
get into the urine. Most urine infections are due to bacteria that
normally live in your own bowel. They cause no harm in the bowel but
can cause infection if they get into other parts of your body. Some
bacteria lie around the anus (back passage) after passing a stool
(faeces). These bacteria can sometimes travel to the urethra and into
the bladder. Some bacteria thrive in urine and multiply quickly to
cause infection.
The infection is commonly just in the bladder ('cystitis'), but may travel higher up to also affect one or both kidneys.
Nearly
1 in 20 boys, and more than 1 in 10 girls, have at least one urine
infection by the time they are 16 years old. Children under five years
are the most commonly affected.
Some terms used by doctors include:
- Urinary tract infection (UTI) - which means a urine infection somewhere in the urinary tract.
- Lower urinary tract infection - which means the infection is
confined to the bladder and urethra. This is much the same as
'cystitis'.
- Upper urinary tract infection - which means the infection affects a kidney and/or ureter.
- Pyelonephritis - this is another term that means infection of a kidney.
- Loin pain - which is a pain in the side of the abdomen, often coming from a kidney.
Does anything increase the risk of developing a urine infection?
In most cases - no
Most urine infections in children are just 'one of those things' and there is no underlying problem to account for it.
In some cases - a 'retention' of urine in the urinary tract may play a part
When
we pass urine, the bladder should fully empty. This helps to flush out
any bacteria that may have got into the bladder since the last toilet
trip. However, various abnormalities of the urinary tract can make the
urine stay around in the bladder, ureters or kidney - when it should be
travelling down the ureters and emptying completely out of the bladder
when going to the toilet. This may allow any bacteria that get there to
multiply as urine is a good 'food' for some bacteria. Various
situations can cause some 'retention' of urine in the bladder or higher
in the urinary tract, which increases the chance of developing a urine
infection. The following are the most common:
Constipation
If large hard faeces (stools) collect in the rectum (back passage) they
can press on the bladder. The bladder may then not empty fully when the
child passes urine. Treating severe constipation sometimes prevents
recurring urine infections.
Dysfunctional elimination syndrome
This is a condition where a young child repeatedly 'holds on' to urine
and/or faeces. That is, they regularly do not fully empty their bladder
or rectum when they go to the toilet. There is no physical cause for
this (that is, no abnormality in the urinary tract or rectum). The
reason why this occurs is often unclear. Stress or emotional problems
may be the underlying cause.
An abnormality of the urinary tract
Various abnormalities of the urinary tract can cause retention of some
urine. The most common condition is called 'vesico-ureteric reflux'.
This is a problem at the junction where the ureter enters the bladder.
In this condition, urine is passed back (refluxes) up the ureter from
the bladder from time to time. This should not happen - the urine
should only flow downwards out of the bladder when going to the toilet.
This condition makes urine infections more likely. Also, infected urine
that refluxes from the bladder back up to the kidneys may cause kidney
infection, scarring, and damage. In some cases this leads to severe
kidney damage if urine infections recur frequently. Other rare problems
that may be found include kidney stones, or congenital abnormalities of
parts of the urinary tract.
Neurological (nerve) or spinal cord disorders
Anything that affects the bladder emptying or sensation. These are rare in children.
Other conditions
Other conditions that
increase the risk of a urine infection include having diabetes, and a
poorly functioning immune system. For example, children having
chemotherapy.
What are the symptoms of a urine infection?
Young children, toddlers and babies can have various symptoms which may include one or more of:
- Fever (high temperature)
- Vomiting and/or diarrhoea
- Drowsiness
- Crying, going off feeds and generally unwell
- Appear to be in pain
- Blood in urine (uncommon)
- Jaundice (yellowing of the skin)
- Cloudy or smelly urine
Older children, in addition to one or more of the above
symptoms, may also say that they have pain when they pass urine, and
pass urine frequently. If a kidney becomes infected they may also have
shivers, and complain of abdominal (tummy) pain, back pain, or a pain
in a side of the abdomen. Bedwetting in a previously 'dry' child is
sometimes due to a urine infection. Just being 'generally unwell' may
be due to a urine infection.
Note: a urine infection should be
suspected in any child who is unwell or has a fever with no other clear
cause. This is why a urine test is commonly done when a child is
unwell, as a urine infection is important to diagnose and treat
promptly.
How is a urine infection confirmed?
A sample
of urine is needed to confirm the diagnosis. Urine normally has no
bacteria present, or only very few. A urine infection can be confirmed
by urine tests that look for bacteria and/or the effects of infection
in the urine.
Ideally, the sample of urine should not come into
contact with skin or other materials that may contaminate it with other
bacteria. Adults and older children can do this by a 'mid stream'
collection of urine. This is not easy to do in young children and
babies. The following are ways to get a sample of urine that is not
contaminated:
Young children - the usual way is to catch
some urine in the specimen bottle whilst in 'full flow'. Just be ready
with the open bottle as the child passes urine. (Be careful not to
touch the open rim of the bottle with your fingers as this may
contaminate the specimen with bacteria from your fingers.)
Babies -
one method is to place a specially designed absorbent pad in a nappy
(supplied by a doctor). Urine is sucked into a syringe from the wet
pad. Another method is to use a plastic bag that sticks onto the skin
and collects urine. If no pad or plastic bag is available, the
following might work. Take the nappy off about one hour after a feed.
Tap gently with a finger (about once a second) just above the pubic
bone. (This is the bone at the bottom of the abdomen above the
genitals.) Have ready the open bottle. Quite often, within about five
minutes, the baby will pass urine. Try and catch some in the bottle.
If
you collect a sample at home, take it to the doctor or clinic as soon
as possible after collection. If there is a delay, store the urine
sample in the fridge.
What is the treatment of a urine infection in children?
A
course of an antibiotic will usually clear the infection within a few
days. Give lots to drink to prevent dehydration. Also, give paracetamol
to ease any pains and fever (high temperature). Sometimes, for very
young babies or for severe infections, antibiotics are given directly
into a vein through a 'drip'.
What is the outlook (prognosis)?
In most
cases, the outlook is excellent. Once a urine infection is diagnosed
and treated, the infection usually clears away and the child recovers
fully. In many cases, a urine infection is a 'one-off' event. However,
some children have more than one urine infection and some develop
several throughout their childhood ('recurring UTIs').
In some
cases, an infection can be severe, particularly if a kidney becomes
badly infected. This can sometimes be serious, even life threatening in
a minority of cases if treatment is delayed. A bad infection, or
repeated infections, of a kidney may also do some permanent damage to
the kidney. This could lead to kidney problems or high blood pressure
later in life.
When are further tests advised?
Urine infection is common. In most cases, a child with a urine infection will make a full recovery with no ongoing concerns.
Tests
are advised in some cases to check on the kidneys and/or bladder. Your
doctor will advise if your child needs further tests. It depends on
factors such as the child's age, the severity of the infection, and
whether it has happened before. For example, as a general rule:
- Children
over the age of six months who have a 'one off' urine infection which
promptly clears with treatment do not usually need any further tests.
- Children with a severe infection, or with an infection with unusual features, may warrant tests.
- Children with recurring infections of any severity may warrant tests.
The tests that are advised may vary depending on local policies
and the child's age. There are various tests (scans, etc) that can
check on the structure and function of the urinary tract (the kidneys,
ureters, bladder and urethra).
The results of the tests are normal in most cases.
However, in some cases, an abnormality such as vesico-ureteric reflux
may be detected (described above). Depending on whether an abnormality
is detected, and how severe it is, a kidney specialist may advise a
regular daily low dose of an antibiotic. This treatment is advised in
some cases to prevent further urine infections, with the ultimate aim
of preventing damage to the kidneys.
Note: the general 'rules'
as to which children should have further tests following a urine
infection have been laid out in a recent guideline from NICE (National
Institute for Health and Clinical Excellence). The section above tries
to summarize this guideline. However, this guideline is controversial.
Before the publication of this guideline, more children would have
usually had tests. For a flavour of the controversy and debate over
'who needs tests' - see the references at the end of this article.
General tips following a urine infection in a child
If your child has had a urine infection then, to help prevent a further infection in the future:
- Try not to let your child become constipated.
- Make sure your child has plenty to drink each day to regularly 'flush out the bladder'.
Also, see a doctor promptly if you suspect your child has
another urine infection. If this is confirmed, remind your doctor that
your child has had a previous urine infection as further tests may be
advised.
Disclaimer: This article is for information only and should not
be used for the diagnosis or treatment of medical conditions. EMIS and
PiP have used all reasonable care in compiling the information but make
no warranty as to its accuracy. Consult a doctor or other health care
professional for diagnosis and treatment of medical conditions.
© EMIS and PiP 2008 Reviewed: 24 Jul 2008
