Urinary Tract Infections (UTIs) in Children

• Childhood urinary tract infections are fairly common and are generally caused by bacteria. Routine antibiotic therapy is successful in resolving these infections.
• Recurrent UTIs in children may be indicative of malformation or malfunction of the urinary tract.
• Common symptoms and signs of UTIs in children include pain and urgency with urination, blood in the urine, abdominal/pelvic pain, fever, flank pain, and vomiting.
• Some selected children who experience a UTI should have diagnostic studies performed. These children include children less than 2 years of age, any male child, any child who has had more than one UTI, or any child who has had pyelonephritis.
• Several recommendations exist to help lessen the likelihood of a child developing a UTI.

A urinary tract infection is an infection of the bladder (cystitis) or kidney(s) (pyelonephritis). Cystitis is considerably more common than the more severe and more serious pyelonephritis.

Bacteria cause the large majority of urinary tract infections in children. Viral infection of the bladder is less common, while fungal infections of the urinary tract are rare and occur most commonly in immunocompromised individuals (for example, those with HIV/AIDS, chemotherapy recipients).

Risk factors predisposing for childhood UTIs include the following:

1. Male gender, especially uncircumcised infants
2. Poor toilet habits: Children should be encouraged to urinate every two to three hours.
3. Poor toilet hygiene: Females should always wipe front to back to avoid introduction of stool bacteria to the urethral opening.
4. Individuals with a compromised immune system or compromised bladder function (for example, spinal cord injury victims who require self-catheterization)
5. Sexual activity

Characteristic symptoms of a urinary tract infection include

• pain with urination (dysuria),
• urinary frequency (needing to urinate frequently),
• urinary urgency (feeling a compelling urge to urinate), and
• loss of previously established urinary control (for example, bedwetting).

Nonspecific but common symptoms include fever (especially >102.2 F or 39 C) and abdominal pain. For some children less than 2 years of age, these more subtle problems may be the only indicator of a UTI. Associated symptoms of concern include flank pain, fever, and vomiting. Obvious blood in the urine (gross hematuria) as well as a positive family history for childhood urinary tract infections (especially in siblings) are also red flags and should raise the level of concern. Interestingly, the odor and color (with the exception of obvious blood) of the urine are not predictors of a UTI.

Establishing an accurate diagnosis (vs. a presumptive diagnosis) includes determining the causative bacteria of the infection, its antibiotic sensitivity profile, and determining whether any anatomical or functional risk factors are present that might predispose the child to the current infection. Such information is crucial to establish the individual's risk for recurrent urinary tract infections, which can predispose to scarring of the kidney and possibly renal failure (end-stage kidney disease, requiring either dialysis or renal transplant).

The physical examination of a child with suspected urinary tract infection should start with the vital signs (temperature, pulse, breathing rate, and blood pressure, which is often measured with the vital signs). The presence of fever (especially over 102.2 F or 39 C) is highly correlated with the presence of a UTI. Blood pressure and assessment of height and weight provide helpful reassurance if normal or stable long-term renal function. Visual examination of the abdomen for enlargement related to potentially oversized kidney(s) or bladder is important. Tenderness during palpation of the abdomen (especially the suprapubic region containing the bladder) or the flank area (where the kidneys are situated) is very helpful in establishing the diagnosis.

Examination of the genitalia is also very important to see if there is evidence of vaginal irritation (redness, discharge, evidence of trauma or foreign body). An uncircumcised male infant (especially with a foreskin that is difficult to retract) is more likely to experience a UTI when compared to a population of similar infant boys who have been circumcised. Lastly, consideration of other conditions that might be responsible for fever and abdominal pain is important.

Laboratory studies

An abnormal urinalysis (including microscopic examination) may be indicative of a urinary tract infection. However, the urine culture is mandatory in confirming the diagnosis of a UTI. The culture provides both the exact bacterial cause as well as the antibiotic sensitivity profile to successfully treat the infection. In addition, studies have demonstrated a relatively short list of bacteria that commonly cause UTIs. A UTI caused by abnormal bacteria should be a source of concern.

In a toilet-trained child, a clean-catch urine specimen should provide a reliable specimen for culture. A non-toilet-trained child or an uncircumcised boy whose tight foreskin may lead to potential urine specimen contamination should have the specimen obtained by a sterile catheterization. An alternative approach to catheterization is called "suprapubic bladder aspiration." This safe procedure involves passing a small needle through the skin into the urine-filled bladder cavity and aspiration of urine into the attached syringe. Collection of urine in a "urine bag" is not recommended. Some studies have indicated an 85% false-positive rate of UTI diagnosis with this method, prompting unnecessary laboratory and diagnostic studies as well as inappropriately prescribed antibiotic therapy.

Regardless of the mechanism chosen to obtain a child's urine specimen, it is very important to examine the urine as soon as possible since a delay can increase the risk of both false-negative and false-positive results.

Other laboratory studies (for example, complete blood count) are generally not helpful, and their nonspecific values do not provide differentiation between the more significant kidney infection (pyelonephritis) and a less concerning bladder infection (cystitis).

Home remedy suggestions for UTIs in adults are legion, and unfortunately many have no scientific basis in fact. Fewer still have been shown to be safe and possibly effective in children. Those that do fulfill such criteria include the following:

1. Unsweetened cranberry or blueberry juice: These juices reportedly lessen the adherence of infective bacteria to the bladder wall and thus allow them to be expelled in urine.
2. Pineapple: This fruit contains a chemical (bromelain) that reportedly possesses anti-inflammatory properties and thus reduces UTI symptoms.
3. Yogurt: Some studies have indicated a benefit in consumption of this product. The exact mechanism of benefit is unclear at this time.
4. Increase in overall fluid intake (for example, water): This would dilute bacteria concentration and allow more effective "flushing out" of harmful bacteria.

Perhaps the best therapy is prevention.

Once an effective antibiotic has been selected and administered, most patients experience a rapid and permanent resolution of their symptoms. Recurrent UTIs raise a concern regarding anatomical abnormalities of the urinary tract (for example, kidney malformation). Similarly, malfunction of the urinary tract (for example, reflux of urine from the bladder to the kidney) is another condition commonly associated with recurrent UTIs.

Urinary tract infections are not contagious. They are not acquired by sharing a bath with another child who has a UTI. Likewise, they cannot be acquired from sitting on a contaminated toilet seat.

Antibiotic therapy for UTIs is based upon the sensitivity profile obtained from the urine-culture results. Cystitis (infection limited to the bladder) should respond quickly to routine oral antibiotics. Pyelonephritis may need hospitalization for intravenous administration of antibiotics along with fluid therapy if the patient is experiencing associated vomiting and dehydration. Oral antibiotic therapy, however, may be appropriate if these complications are not present.

The American Academy of Pediatrics has issued a position statement recommending follow-up studies for children who have experienced a urinary tract infection. Children who should be further evaluated include

• children 2 months of age to 2 years of age who sustain their first UTI,
• any male child who experiences a UTI,
• any child 3 years and older who has had more than one UTI, and
• any child who has had pyelonephritis.

The purpose of the studies detailed below is to accurately define the anatomy and functional physiology of these children who may be at risk for renal scarring and possible complete kidney failure.

• Renal ultrasound: This procedure helps to define the renal anatomy (kidney location, size, shape).
• VCUG (voiding cysto-urethrogram): This test involves passage of a catheter into the bladder to fill it with dye. After removal of the catheter, the bladder will empty. A radiologist performs imaging studies to monitor for complete bladder emptying without obstruction and/or backward flow (reflux) of the dye from the bladder into to ureters and up to the kidneys.
• Renal scan: This test uses a small amount of radioactive material (radioisotope) to measure the function of the kidneys. It is designed to evaluate the functional capability of the kidneys and evaluate for possible renal scarring.
• IVP (intravenous pyelogram): This is a rarely used test involving injecting dye into the bloodstream via an IV (The dye is excreted via the kidneys.) and then obtaining X-ray images. The renal ultrasound and renal scan have replaced the usefulness of this test.

There are several suggestions that have been made by pediatric urologists to lessen the likelihood of children developing urinary tract infections. These include the following:

1. Hygiene: Wipe females from front to back during diaper changes or after using the toilet in older girls. With uncircumcised males, mild and gentle traction of the foreskin helps to expose the urethral opening. Most boys are able to fully retract the foreskin by 4 years of age.
2. Complete bladder emptying: Some toilet-trained children are in hurry to leave the bathroom. Encourage "double voiding" (urinating immediately after finishing the first void). Children should be encouraged to urinate approximately every two to three hours. Some children ignore the sensation of a full bladder in the desire to continue to play.
3. Avoid the "4 Cs": carbonated drinks, high amounts of citrus, caffeine (sodas), and chocolate. Some kidney specialists are not as adamant about this option.
4. Avoid bubble baths: Some renal specialists also view this recommendation with skepticism.
5. Encourage cranberry juice: Similar to the above "4 Cs," some specialists view this suggestion as folklore.
6. Prophylactic antibiotics: Daily low-dose antibiotics under a doctor's supervision may be used in children with recurrent UTIs or in those with anatomic or physiologic factors that predispose to UTIs.

Children who experience a UTI generally have an excellent prognosis. If a child's UTI is associated with a red flag or high-risk characteristic (for example, male gender, usual type of bacteria, pyelonephritis, etc.), appropriate follow-up studies (renal ultrasound, renal scan, and VCUG) will help to alert the doctor about unrecognized problems. These additional studies can help avoid progressive loss of kidney function or other health issues that might not be detected.