Urinary Tract Infection

Posted in Disease Information

Introduction

A urinary tract infection (UTI) is a common infection that occurs in the urinary tract (any part of the body used to make and get rid of urine).

Symptoms of a UTI in babies and infants include:

• Vomiting
• High temperature of or above 38°C (100.4°F)
• Irritability
• Appearing lazy and sluggish (lethargic)

Symptoms of a UTI in older children include:

• frequent passing of urine
• complaining of pain or a burning sensation when passing urine

When to seek medical advice

Always contact Dr. B C Shah if you think your child has a UTI. This is not usually a serious type of infection but it does need to be properly diagnosed and treated by a doctor.

Treatment

Most cases of UTIs can be successfully treated with antibiotics.

As a precaution, babies under three months old are usually admitted to hospital, as are children with more severe symptoms.

Many older children can be treated safely at home.

What is the urinary tract?

The urinary tract is where our bodies make and get rid of urine. It is made up of:

• The kidneys: two bean-shaped organs that make urine out of waste materials from the blood
• The ureters: tubes that run from the kidneys to the bladder
• The bladder: where urine is stored until we go to the toilet
• The urethra: the tube through which urine passes out of the body

Causes

UTIs develop when part of the urinary tract becomes infected, usually by bacteria. Bacteria can enter the urinary system through the urethra or, more rarely, through the bloodstream.

In many cases of urinary tract infection in children, there is no apparent cause. However, several factors which increase the risk of a UTI developing include:

• Constipation, which can place pressure on the bladder, making it more vulnerable to infection
• Dysfunctional voiding: a relatively common childhood condition where a child ‘holds on’ to their urine even though they have an urge to urinate

Types of urinary tract infection

There are two types of UTI:

• A lower UTI is an infection of the lower part of the urinary tract, which includes the bladder and the urethra. An infection of the bladder is called cystitis, and an infection of the urethra is known as urethritis.
• An upper UTI is an infection of the upper part of the urinary tract, which includes the kidneys and the ureters. Upper UTIs are potentially more serious  because there is a risk of kidney damage. An infection of the kidneys is known as pyelonephritis.

Who is affected

UTIs are a relatively common infection during childhood.

During the first year of life they are more common in boys then girls, but this changes as children grow older.

It is estimated that around 1 in 10 girls and 1 in 50 boys will develop a UTI at some point between their first and second birthday.

The frequency of infection drops as children grow older, but can rise in women again once they become sexually active (sexual activity is a risk factor for UTIs in adults).

Outlook

Treatment for UTIs in children is usually very effective, with symptoms cleared up quickly.

It is important to always seek prompt treatment if you think your child has a UTI (or any other type of infection), as if left untreated complications can occur, such as:

• Scarring of the kidneys, which in later life can cause high blood pressure
• Kidney disease

Symptoms of UTIs in children

Symptoms of childhood urinary tract infections (UTIs) can vary depending on the age of the child.

Babies under three months

In babies under three months, symptoms of a UTI (ranked in order of most common to least common) are:

• High temperature of or above 38°C (100.4°F)
• Vomiting
• Lethargy (lack of energy)
• Irritability
• Poor feeding
• Failure to thrive (not developing at the expected rate)
• Abdominal pain
• Yellowing of the skin and whites of the eyes (jaundice)
• Blood in their urine
• Unpleasant smelling urine

Older infants

In infants older than three months but not old enough to talk, symptoms of a UTI (ranked in order of most to least common) are:

• High temperature of or above 38°C (100.4°F)
• Abdominal pain
• A feeling of tenderness around their pelvis
• Vomiting
• Poor feeding
• Lethargy
• Irritability
• Blood in their urine
• Unpleasant smelling urine
• Failure to thrive

In children old enough to talk, symptoms of a UTI (ranked in order of most to least common) are:

• A frequent need to urinate
• Pain or a burning sensation during urination (dysuria)
• D51eliberately holding in their urine
• A change in their normal toilet habits, such as wetting themselves or wetting the bed
• A feeling of tenderness around their pelvis
• Fever
• A general sense of feeling unwell
• Blood in their urine
• Unpleasant smelling urine
• Cloudy urine

When to seek medical advice

You should always contact Dr. B C Shah if your child develops any symptoms listed above.

Most UTIs that occur during childhood are mild and are not a cause for concern, but do usually require treatment with antibiotics to reduce the duration of infection and any risk of complications.

Causes of UTI

Most urinary tract infections (UTIs) are caused by bacteria that live in the digestive system. If these bacteria get into the urethra (the tube through which urine passes), they can cause infection.

In young children this can often occur when they wipe their bottom after going to the toilet, and soiled toilet paper comes in contact with their genitals.

Young girls are more at risk than boys from UTIs because there is less distance between their bottom and their urethra.

Babies who soil their nappies can also sometimes get small particles of stool into their urethra. Modern nappies are designed to prevent this, but it can occur by accident if a baby squirms a lot when being changed.

There are also several conditions that can increase the risk of UTIs occurring. These are outlined below.

Constipation

Constipation does not usually have obvious causes, but can sometimes result from lack of fibre in a child’s diet. Constipation is a relatively common condition among children.

Constipation can cause the rectum (the part of the large intestine that connects to the anus) to swell, which can put pressure on the bladder, preventing it from emptying normally. The remaining urine can then become infected by bacteria.

Read more about constipation in children.

Dysfunctional voiding

Dysfunctional voiding is a relatively common condition among children. It occurs when a child ‘holds on’ to their urine even though they have the urge to urinate. This can occur as a result of nerve damage, but can also be due to habit, which may be difficult for the child to break.

For example, young children at playschool or primary school may be nervous or embarrassed about asking to use the toilet, so they may hold onto their urine until they go home.

Children usually grow out of dysfunctional voiding as they start to adopt more regular bathroom habits. However, some children may need special training.

Vesicoureteral reflux

Vesicoureteral reflux is an uncommon condition in which urine leaks back up from the bladder into the ureters and kidneys. It is estimated that one in 50 girls and one in 200 boys under the age of 12 are affected by vesicoureteral reflux.

There are two types of vesicoureteral reflux:

• Primary vesicoureteral reflux is caused by a defect present before birth. There is usually a valve between the bladder and the ureters that prevents urine leaking back out of the bladder. In children who have primary vesicoureteral reflux, the valve does not function properly, and urine is able to flow out of the bladder and back up the ureter to the kidney.
• Secondary vesicoureteral reflux is caused by a condition that occurs after birth. For example, urine flow from the bladder may be blocked, or a lower UTI may cause the ureters to become so inflamed and swollen that the one-way valves in the ureters fail, allowing urine to flow both ways.

The danger with vesicoureteral reflux is that a lower UTI can quickly turn into a more dangerous upper UTI, because infected urine can move out of the bladder and back into the ureters and kidneys.

Primary vesicoureteral reflux usually clears up in children as they get older. However, if it is felt a child has a high risk of developing upper UTIs, they may be prescribed an antibiotic to take in the long-term.

Although UTIs can easily be treated with antibiotics and risk of complications is low, if left untreated they can cause kidney scarring. Scarring can occur over time when there is a backup of urine that exposes the kidneys to higher-than-normal pressure. Extensive scarring may lead to high blood pressure and end-stage kidney disease (also known as kidney failure), where kidneys lose most or all of their functioning abilities.

If a child has severe, persistent or recurring vesicoureteral reflux, then surgery is sometimes a treatment option.

Diagnosing UTIs

Children with symptoms of a urinary tract infection (UTI) should always have their urine tested because an accurate diagnosis is important for treatment.

An exception may be made for girls over three years of age who have typical symptoms of cystitis (infection of the bladder), such as urinating more frequently and pain when passing urine.

Urine sample

A urine test is also useful for ruling out other conditions that can cause similar symptoms, such as type 1 diabetes.

If your child has a temperature of 38°C (100.4°F) or above (a fever), and the doctor  is unable to find an obvious cause, your child’s urine should be tested within 24 hours.

If your child does not have a fever but has other symptoms of a UTI, a urine test will still be required. However, the urine test does not need to be carried out as quickly, and it might be reasonable to wait more than 24 hours to have it done.

In young children, it is very important to make an accurate diagnosis. However, it can be difficult to obtain a clean urine sample from young children because they are often unable to pass urine into a specimen bottle. Also, if the inside rim of the specimen bottle is touched, it will affect the quality of the sample. Therefore, it may be necessary to carry out the test in hospital where health professionals with skill in obtaining a sample are available.

If there is an urgent need to obtain a sample then a small plastic tube, called a catheter, can be placed into your child’s urethra (the tube through which urine passes out of the body). The catheter will be guided up into the bladder and used to drain out a small sample of urine for testing.

This tends to only be used in more serious cases as children can find the experience upsetting.

Further testing

Further testing is usually only required if your child’s UTI symptoms are different from common symptoms (atypical). Examples of atypical symptoms include:

• Being seriously ill
• Reduced urine flow
• A noticeable lump or mass in their abdomen (stomach) or bladder
• Testing which shows the bacteria has spread from their urinary tract to their blood
• They failed to respond to antibiotic treatment within 48 hours
• The infection was caused by bacteria other than the Eschericia coli (E. coli) bacteria

Further testing is also required if your child has previously had:

• Two or more upper UTIs
• One upper UTI, plus one or more lower UTIs
• Three or more lower UTIs

A typical symptoms and recurring UTIs could be due to underlying problems with your child’s urinary tract infection that will require further investigation.

Tests and procedures commonly used to investigate the urinary tract are described below.

Ultrasound scan

An ultrasound scan is usually the first procedure used to assess the urinary tract. The ultrasound scan uses sound waves to build up a picture of the inside of your child’s body.

An ultrasound scan is a useful way of assessing whether there are any obvious abnormalities in your child’s urinary tract, such as an unusually narrow ureter (the tube that runs from the kidneys to the bladder) a bladder stone, or kidney stone.

DMSA Scan

A dimercaptosuccinic acid (DMSA) scan is used to assess the state of the kidney. A DMSA scan is usually carried out six months after an acute atypical UTI (a UTI with unusual symptoms) or after the last episode of a series of recurring UTIs.

A DMSA scan is used to assess whether your child’s kidneys have been damaged, or if there are any abnormalities with the kidneys that are making them vulnerable to recurring UTIs. DMSA is a mildly radioactive substance that shows up on a special camera, known as a gamma camera.

During the procedure, your child will be injected with DMSA. After an hour, the DMSA will build up inside the kidneys. DMSA only attaches itself to healthy tissue, so is a useful method of locating any damaged kidney tissue.

The gamma camera is used to take a series of pictures of your child’s kidneys. It usually takes about 30 minutes to complete the scan. During this time it is important for your child to remain as still as possible, so it may be a good idea to bring their favourite book or toy to help them relax during the scan.

A DMSA scan is not painful because local anaesthetic is used to numb the site of the injection. However, the gamma camera is quite large, so younger children may find the experience upsetting. Explaining exactly what will happen and what to expect before the scan may help reassure your child.

After the scan, the DMSA will pass harmlessly out of your child’s body in their urine. Their urine will be slightly radioactive, but is not harmful to your child or other people. However, as a precaution, it is recommended you wash your hands after changing your child’s nappy, and dispose their nappies in a sealed plastic bag.

Micturating cystourethrogram (MCUG)

Micturating cystourethrogram (MCUG) is a procedure used to study the bladder rather than the kidneys.

MCUG is used to check your child does not have vesicoureteral reflux (a condition where urine leaks back up from the bladder towards the kidneys). As with a DMSA scan, it is important for your child to stay as still as possible during the MCUG procedure. Very young children and babies may need to be wrapped tightly in blankets to help prevent them moving during the procedure.

During MCUG, your child will lie on a bed or treatment table and a catheter will be used to pass a special type of liquid, known as a contrast agent, into their bladder. Like DMSA, the contrast agent shows up very clearly on an X-ray.

An X-ray film will then be taken as the contrast agent is passed out of your child’s bladder, in the same way that their urine passes out.

If the X-ray film shows some of the contrast agent leaking back out of the bladder towards the kidneys, it is likely that your child has vesicoureteral reflux.

Most cases of vesicoureteral reflux resolve without the need for treatment as a child gets older. Your child may be prescribed a long-term course of low-dose antibiotics to help prevent them from developing another UTI, until the condition resolves.

The MCUG procedure is not painful and takes around 30 minutes to complete. However, it is likely your child will feel mild discomfort when the catheter is first inserted into their urethra.

The X-rays will expose your child to a low dose of radiation that is entirely safe. The levels of radiation used are the same as the amount of radiation your child would be exposed to by natural sources (background radiation) over the course of three to six months.

Treating UTIs

If your child is younger than three months old, they will be referred to a doctor who specialises in the care of children (paediatrician).

Your baby will usually be treated in hospital using an intravenous drip (where a tube containing antibiotics is directly connected to their vein). They should recover from the UTI within 24 to 48 hours.

Children over three months old

If your child is over three months old and it is felt they are at risk of serious complications, then you can contact Dr. B C Shah.

Signs that indicate your child may develop serious complications from a UTI include:

• A recurring high temperature of 38°C (100.4°F) or above
• Dehydration, which can cause them to appear drowsy and have few or no tears when crying
• Being sick
• A known condition that affects their urinary system
• A history of kidney disease in your family

If your child is very young, Dr. B C Shah may decide to refer them for hospital treatment, even if there is not an obvious risk they will develop serious complications.

If it is felt there is no risk of serious complications developing, or if the risk is low, you may be able to treat your child at home. The infection can be treated using oral antibiotics, and paracetamol can be used to treat symptoms of fever or discomfort.

For lower UTIs, a three-day course of antibiotics is usually recommended. For upper UTIs, a seven-day course of antibiotics is usually recommended. Children who are unable to swallow tablets or capsules can be given antibiotics and paracetamol in liquid form.

Your child should recover from the UTI within 24 to 48 hours. However, it is very important they finish the prescribed course of antibiotics to prevent the infection recurring.

After taking antibiotics, some children may experience side effects. However, any side effects will usually pass after your child stops taking the antibiotics. Side effects may include:

• Feeling sick (nausea)
• Vomiting
• Upset stomach
• Diarrhoea
• Loss of appetite

A very small number of children (less than one in 5,000) may experience a severe allergic reaction (anaphylaxis) to antibiotics that contain penicillin. Symptoms of an allergic reaction to penicillin include:

• A rash
• Swelling of the hands, feet and face
• Shortness of breath

If your child experiences these symptoms, you should immediately dial 999 for an ambulance and tell the operator you think anaphylaxis has occurred.

Treating constipation

It is important to treat constipation in children promptly because it is a major risk factor for developing UTIs.

As with babies and adults, children with constipation will first be advised to change their diet. If this fails, laxatives can be prescribed. An osmotic laxative is usually prescribed, followed if necessary by a stimulant laxative.

Osmotic laxatives increase the amount of fluid in your child’s bowels. This helps to soften your child’s stools, making it easier for them to pass them out of their body.

Stimulant laxatives stimulate the muscles that line the digestive tract, helping to move stools along your child’s large intestine to their anus (the point at which waste products leave the body).

As well as eating plenty of fruit, older children should have a well balanced diet that contains vegetables and wholegrain foods, such as wholemeal bread and pasta.

Surgery

Surgery is usually only recommended if :

• Your child has severe, persistent or recurring vesicoureteral reflux (where urine leaks back up from the bladder and into the ureters and kidneys), and
• They are having reoccurring UTIs that could result in permanent scarring of their kidneys

Surgery aims to repair the valve between the bladder and each affected ureter that keeps it from closing and stopping urine from flowing backward. The two types of surgery used are:

• Open surgery. This type of surgery is performed under general anaesthetic and your child will usually need to stay in hospital for a few days. A catheter may be used to drain your child’s bladder. The risks of open surgery can include infection, blood clots and bleeding.
• Endoscopic surgery. This type of surgery is less invasive compared to open surgery but is not always as effective. A cystoscopy allows the doctor to see inside your child’s bladder and inject a bulking agent to try to strengthen the defective valve. Endoscopic surgery is also performed under general anaesthetic, but can usually be performed as an outpatient procedure rather than needing an overnight stay.

Preventing UTIs

It is not possible to prevent all childhood urinary tract infections (UTIs), but the advice listed below may help reduce their frequency.

• Breastfeeding your baby may lower the risk of them developing a UTI. However, the effect takes time to build up, only providing protection after three months of breastfeeding.
• Encourage your child to wipe their bottom from front to back. This will help to minimise the chances of bacteria entering the urethra (the tube through which urine passes).
• Encourage boys to clean around their foreskin regularly. Bacteria can build up there and enter the urethra. If your child’s foreskin is still fixed (does not retract), you should not attempt to clean under it because doing so may damage the surrounding area.
• Encourage children to go to the toilet regularly – at least every four hours, and before having a bath and going to bed.
• Avoid nylon and other types of synthetic underwear. These can help promote the growth of bacteria. Loose-fitting cotton underwear should be worn instead.
• Drinking cranberry juice can help prevent UTIs, but be careful to limit the amount your child drinks because too much can cause diarrhoea. Three glasses of low-sugar cranberry juice a day is a safe amount for most children. Cranberry juice is not suitable for children with diabetes, or for those taking warfarin (a blood-thinning medicine). Higher-strength cranberry capsules are also available, but are not suitable for children aged under 12.

Recurrent urinary tract infections

A small number of children have recurring UTIs. If your child has previously had a UTI, it is important both of you watch for the return of any associated symptoms.

Tell Dr. B C Shah of any symptoms as soon as possible so a diagnosis can be confirmed and treatment can begin.