Urinary Tract Infection In Children

Urinary tract infection is bacterial infection of the urinary system and may involve the bladder or upper urinary tract. In infants, UTI commonly presents as fever without localizing urinary symptoms.

Escherichia coli is the dominant pathogen.

Recurrent infection or atypical organisms may indicate vesicoureteric reflux, obstruction or another structural urinary abnormality.

Infants may present with:

• Fever
• Poor feeding
• Vomiting
• Irritability
• Lethargy
• Failure to thrive
• Jaundice in young infants

Older children may develop:

• Dysuria
• Frequency
• Urgency
• Suprapubic pain
• New onset incontinence
• Abdominal pain

Upper UTI or pyelonephritis is suggested by:

• Fever
• Flank or loin pain
• Vomiting
• Systemic illness

Obtain urine before antibiotics whenever possible. (Nice)

Preferred collection methods are:

• Clean catch urine
• Catheter specimen when reliable clean catch cannot be obtained
• Suprapubic aspiration in selected infants

Bag specimens are prone to contamination and should not be used to definitively diagnose UTI from culture.

Perform:

• Urinalysis
• Microscopy
• Urine culture and susceptibility

Pyuria plus growth of a significant uropathogen supports diagnosis.

Interpret colony count according to collection method.

Recurrent or atypical UTI may require renal ultrasound and further urinary tract imaging according to age and clinical pattern.

Start antibiotics promptly once UTI is sufficiently likely, especially in infants and febrile children.

• Lower UTI

Appropriate oral options include:

• Nitrofurantoin, using age appropriate weight dosing, when renal function is adequate

• Trimethoprim, where local susceptibility supports use

• Cefalexin 12.5 to 25 mg/kg/dose PO every 8 hours, maximum 1 g per dose, depending on severity and local protocol

Typical duration is 3 days for uncomplicated lower UTI in older children, with longer courses where clinically indicated. (Nice)

• Pyelonephritis or febrile UTI

Use an oral or IV agent with adequate renal tissue penetration.

A common inpatient option is:

Ceftriaxone 50 mg/kg IV once daily, maximum 2 g/day

Switch to oral therapy once clinically improved and complete approximately 7 to 10 days total treatment, depending on age, severity and organism.

Infants younger than 3 months, septic children, children unable to tolerate oral treatment, or those with suspected obstruction require admission and IV therapy.

Review culture results and narrow antibiotics according to susceptibility.