1

The classic symptoms of urinary tract infection include dysuria, urgency, and frequency. What are the most common signs of urinary tract infection in preverbal and nonverbal children?

Urinary tract infection (UTI) may present with a myriad of signs and symptoms. In the neonate, UTI may present as fever or sepsis without obvious source. In infants, as well, fever may be the only symptom. Other manifestations of UTIs can be nonspecific. Systemic symptoms may include irritability, fatigue, fussiness, decreased oral intake, decreased urine output, or failure to thrive. Gastrointestinal (GI) symptoms are common and may include vomiting, diarrhea, and abdominal (especially suprapubic) or back pain. This may lead caregivers to conclude the patient has gastroenteritis or a food allergy.

Beyond 2–3 years of age, symptoms more often point to the urinary tract; these include frequency, urgency, retention or incontinence, dysuria, and occasionally hematuria. This can present as a previously toilet-trained child beginning to have “accidents.”

Foul-smelling urine is often mentioned by caregivers but has little diagnostic meaning.

In children who lack bladder sensation (e.g., spina bifida) and who receive regular straight catheterization, change in the quality of the urine (more cloudy, change in odor) may be the only sign. Such children may also present with fever, change in level of alertness, or vomiting.

2

When should a urinalysis be obtained in a child with suspected UTI?

For an infant less than 2 months of age, urinalysis should always be obtained as part of the complete evaluation of fever without a source. For children over 2 months of age, the decision to obtain urinalysis is guided by the child’s clinical status. Once antimicrobial therapy is initiated, the opportunity to make a definitive diagnosis is lost; therefore, urinalysis and culture should be obtained prior to therapy. In any child with unexplained fever and toxic appearance prompting the clinician to give antibiotics, a urinalysis and culture should be obtained prior to initiation of antibiotic therapy.

If a child with an unexplained fever does not need immediate antibiotic treatment, the clinician can assess the likelihood of UTI. Laboratory investigation for UTI should be reserved for those children with concerning symptoms including dysuria, urgency, frequency, suprapubic pain, fever with no obvious source, fever with emesis (and absence of diarrhea), costovertebral angle tenderness, or irritability without an alternate explanation.

The approximate rate of UTI in febrile children 2–24 months of age is 5%; the risk is significantly lower for circumcised boys. Higher risk of UTI can be predicted for children with prior history of UTI, those of non-black race, and those with higher temperatures (>39°C), longer duration of fever (>24 hours), or signs of systemic toxicity. For children deemed to be at low risk, no urinalysis or culture and close clinical follow-up is recommended. For children with one or more risk factors, urinalysis is recommended, and if pyuria is present culture should be obtained to confirm UTI.

3

When and how should urine be obtained for culture in a child with suspected UTI?

If antimicrobial therapy is to be initiated, then a urine specimen suitable for culture should be obtained before antimicrobial agents are given. Urine specimens suitable for culture include those obtained by clean catch midstream collection, urethral catheterization, or suprapubic aspiration. Adhesive bag urine collection is often used for children who are not yet toilet trained. Such bag specimens may be used for urinalysis (UA) but should be assumed to be contaminated with perineal flora and not be used for culture.

One option is to obtain a urinalysis with a bag specimen, and if the UA is normal and the patient is otherwise not at high risk for UTI, the evaluation can be considered complete. If the UA is abnormal, urine should be sent for culture to confirm the diagnosis and provide bacterial identification and sensitivities.

4

What are the alternative methods for urine to be obtained for culture from children of various ages?

Culture samples may only be obtained via catheterization or suprapubic aspiration. Cultures of urine specimens collected in a bag applied to the perineum have an unacceptably high false-positive rate and are valid only when they yield negative results.

Ideal handling of a bagged urine specimen includes (a) the perineal skin is well cleansed before bag application, (b) the bag is removed promptly after voiding, and (c) the specimen is refrigerated or processed immediately. Despite claims that this collection technique has a low contamination rate with ideal handling, there is unavoidable but significant contamination in the two groups at highest risk for UTI—the vagina in girls and the prepuce in uncircumcised boys.

5

How can you differentiate pyelonephritis from cystitis in pediatric patients?

Distinguishing pyelonephritis from cystitis is difficult in young patients because they may have clinical overlap and younger patients often have only nonspecific symptoms. Hence, pyelonephritis and cystitis are often discussed together as one clinical entity, generically covered by the term “urinary tract infection.”

While strict differentiation between upper and lower tract disease in children is often not feasible, there are some features more suggestive of pyelonephritis: high fever (>40°C), ill or toxic appearance, flank pain, or costovertebral angle tenderness and emesis.

Features suggestive of limited cystitis include well appearance, suprapubic pain, and normothermia or low-grade fever.

6

What are some widely accepted empiric antibiotic strategies for pediatric UTI?

Oral or parenteral treatment is equally efficacious for most pediatric UTI (cystitis or pyelonephritis). Antibiotic choice should be based on local antimicrobial sensitivity patterns (if available) and should be individually adjusted to sensitivity testing from the patient’s urine culture.

There is no single preferred duration of therapy, but most recent guidelines suggest at least 3–5 days for simple cystitis and 7–14 days for febrile UTI. Evidence in treatment of pediatric UTI shows shorter (1–3 days) courses inferior to courses in the recommended range.

Intravenous (IV; parenteral) antibiotic therapy should be initiated if the patient is less than 2 months of age, has a toxic appearance, cannot tolerate oral intake, has other adverse anatomic factors (e.g., obstruction to urinary flow), or has a known positive culture for a pathogen not susceptible to oral agents ( Boxes 21.1 and 21.2 ).

It is essential to know local susceptibility patterns, because there is substantial geographic variability. Up to 60% of Escherichia coli strains demonstrate resistance to ampicillin and amoxicillin/clavulanate; therefore, these drugs should not be used as monotherapy unless local patterns of susceptibility are known to be favorable.

7

How does antibiotic therapy for children with pyelonephritis differ from therapy for cystitis?

Historically, treatment of pyelonephritis has been initiated with IV antibiotics until the patient becomes afebrile. This may still be warranted in ill-appearing children or those with complicating factors. However, ample evidence supports outpatient treatment of uncomplicated pediatric pyelonephritis when the child can tolerate oral fluids and antibiotics, has normal renal function, and is not septic. The widely recommended treatment course is 7–14 days of an oral cephalosporin (e.g., cephalexin, cefdinir, cefixime, or cefpodoxime). It is important to note that nitrofurantoin should not be used for suspected pyelonephritis because it does not achieve therapeutic concentrations in the bloodstream.