Introduction

A pediatric kidney infection is a condition affecting children, Kidney infections can severely damage kidneys making them unable to do their job, which is filtering blood, this can lead to waste and fluid build up, causing several other issues.

Kidney infection can cause sudden or long-lasting effects which can lead to kidney failure, recognizing the signs of kidney infection is vital to avoid long lasting side effects and treat the condition tempestively.

In this text we are going to discover what kidney infections are, how they manifest in children and how they can be managed.

What are kidney Infections?

Kidney infections fall under the category of Urinary tract infections also defined as pyelonephritis which is a medical term that means infection of the kidneys.³ A kidney infection can be caused by bacteria spreading from the bladder to the kidneys, excessive bacteria can cause inflammation triggering the kidneys to produce more urine and leading to dehydration.

The combined effect of dehydration and inflammation can lead to scarring of the tissue that composes the kidneys resulting in lower kidney function and higher blood pressure.⁵

So what can cause kidney infection in children?

Common Causes

Bacteria

The most common cause of acute kidney infection is bacteria. Bacteria are germs which can enter from the urethra, (the component of the urinary system from which urine comes out) and travel through other parts such as the bladder and ureter (which transport urine from kidneys to bladder) ending up in the kidneys.⁵

While the infection of the bladder is called cystitis, the progression of this condition can occasionally progress to kidney infection of one or both kidneys.^4,5

In most cases kidney infections are caused by E. coli (up to almost 80% of cases), this bacteria normally lives in the intestines, however when this bacteria travels to the bladder it can lead to cystitis and if it progresses further to kidney infection.

Other families of bacteria which can cause kidney infections are Klebsiella, Proteus, Pseudomonas, Enterococcus, and Staphylococcus saprophyticus.¹⁰

Viral and fungal

Kidney infection can also be caused by viral or fungal infections, this type of infection is less common, however an example of viruses which can lead to infection are the hepatitis family of viruses (B, C, and E) and the varicella zoster virus.⁹

Fungal infections are also rare however organisms such as Candida, Mucor, Aspergillus and many others can cause fungal infections in the presence of major risk factors such as gender, length of antibiotic use, and surgical procedures.

What are the mechanisms of infection?

Bacteria can spread in different ways in the body, we can classify the spread of infection in two categories, the first is called haematogenous spread, the second is from an already present infection of the lower urinary tract, so what does this mean?

• Haematogenous spread is uncommon, and can happen to patients with a weaker immune system or when someone has a blockage of the ureter, one or both tubes in charge of the tranport of urine from the kidney to the bladder
• Ascending infection is most simple when bacteria from the bowels come into contact with the urethra (the opening from which urine exits), causing these bacteria to travel to the bladder and in certain cases to the kidneys⁸

Who is at risk of having a kidney infection?

Some children might be more at risk of contracting kidney infections in fact children with conditions such as vesicoureteral reflux (VUR), an uncommon congenital condition in which instead of lowing out urine flows backwards from the bladder to the kidney, this condition has been diagnosed in up to 40% of children with urinary tract infections.⁸

Neurogenic bladder, a condition that leads to a lack of control of the bladder due to neuronal problems (problems of the brain, spinal cord or nerves), this condition can affect the way the bladder works by keeping it too full or emptying at the wrong moments if the bladder is too full, urine might back up into the kidneys which can cause infection.⁶

Bladder obstructions, a bladder or urinary obstruction is a condition in which urine cannot exit properly from the body or flows the wrong way causing urine build up 

In certain cases, kidney infection can develop without a bladder infection for example in the case of kidney stones or diabetes. Poor toilet and hygiene habits or a family history of urinary tract are also important factors.

It is important to note that girls are generally more affected than boys because girls urethras are shorter and more accessible to bacteria, however, uncircumcised boys younger than 1 are also at risk^4,5,8

What are the signs and symptoms of kidney infection in children?

Kidney infection symptoms can vary based on age

• Infants, babies usually show no fever followed by poor feedings and vomiting
• Children younger than 2 might only have a fever without any other symptoms or might also have diarrhoea, vomiting and poor appetite
• Children above 2 might have a fever, changes to appetite, pain in the lower back and stomach and frequent urge to urinate with pain.^4,5
• General symptoms in children with kidney infection might include
• Blood in urines
• Urine with a bad smell
• Wetting the bed
• Stomach pain (complaining about tummy ache)
• High temperature
• Lack of appetite
• Complaining or crying when urinating^4,5

How is kidney infection diagnosed?

To diagnose kidney infection the healthcare professional would usually:

• Look at your child’s symptoms and history.
• Perform laboratory tests including urine analysis (urinalysis) and blood tests.
• Perform imaging studies, these are not always needed but can be carried out if your child is considered high risk, or in case the infection is more complex (for example if the infection is unresponsive to treatments, if your child has fevers lasting more than 48 hours, has received a transplant, has diabetes)
• Imaging can include Ultrasounds, MRI, a CT scan for the abdomen and pelvis, while most patients usually only have an infected kidney, in some cases both kidneys are involved making who is affected look sicker, having a faster disease progression and making them more likely to develop kidney injury (kidney damage which can lead to loss of function), in this cases the use of imaging studies can help understand if one or more kidneys are involved.⁸

Treatment

Generally any type of urinary tract infection, of which kidney infections are part is managed with antibiotics, this is however true only if the infection is bacterial.

In Children a kidney infection will be treated in the hospital where Most of the Urinary tract infections are treated within 7 days, however, symptoms might take a bit more to clear up,

Painkillers might be prescribed to help manage your child's pain and lower their body temperature (If advised by the doctor).⁴

Managing Kidney infections and UTIs

• Help your child keep himself or herself hydrated, An important factor in clearing your child's kidneys from the infection is a good flow of urine, in fact it is recommended by healthcare professionals that your child drink plenty of water to allow regular peeing and prevent constipation
• Applying heat on the lower belly back or side with a heat pad or simply helping    your child take a hot bath might also help relieve pain.
• Remove the Obstruction surgically, in some cases, the obstruction might need to be surgically removed to prevent urine stagnation in the bladder, this might mean that your child will not be able to to urinate on his/her own and might need your help with the suggestion and instruction of the healthcare professional to regularly drain the urine through a catheter from their bladder³
• After treatment the healthcare professional might want to carry out additional testing  to exclude any kidney damage.

How can you help your child from getting a kidney infection?

Good Hygiene, for boys this means keeping the tip of the penis clean while for girls wiping from front to back to prevent infection

• Avoid constipation, teach your child to use the washroom when feeling the urge instead of waiting until they reach home and teach them to drink plenty of water
• Teach your child to empty their bladder before going to sleep
• Treat the infection as quickly as possible, if your child laments about pain when using the toilet or you notice an increase in toilet use, there is a good chance your child is suffering from an infection, treating it tempestively can prevent the infection from spreading to the kidney.¹²

Summary

In conclusion, pediatric kidney infections are of significant concern in children's health, when a child is affected it is important to intervene with an early diagnosis and management to prevent long lasting and irreversible complications.

Understanding Signs symptoms and how to manage this condition, can help any parent learn how to identify any indicators of this condition, also helping health care providers provide a fast and effective treatment.

If your child shows any sign of fever, or appears sick, taking them to a healthcare professional might be the best option, if kidney disease is left untreated it can spread through the blood causing kidney damage, failure and can be life-threatening.