Urinary Tract Infections

Clinical Presentation

Presentations are variable amongst age groups, but classically involve fevers, irritability, and dysuria. Polyuria and hematuria may be observed in some cases.

In young infants, fever may be the only presenting symptom. With a high enough clinical suspicion, diagnosis can be made via a catheterized urine sample. 

Diagnosis is confirmed by UA, which will demonstrate pyuria. Typically, 50,000 colonies per mL of a single uropathogenic organism is sufficient to clinch the diagnosis. 

 

Treatment

The ultimate goal should always be to tailor therapy toward culture speciation and sensitivities

In non-pregnant patients, asymptomatic bacteriuria in general does not require antibiotic treatment

  • Presumptive antibiotic (Abx) therapy is directed against common causative organisms:
    • E. coli 70-85%
    • Others include Klebsiella pneumoniae, Group B Streptococcus, Proteus mirabilis, Enterobacter, Staphylocoocus saprophyticus, Citrobacter, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans
    • Gram positive organism are uncommon pathogens of UTIs in children
    • Consideration must be given to children with recurrent UTI's, and review of their more predominate organisms and sensitivity patterns can help guide presumptive care pending the culture results.
    • Therapy also depends on extent of ascension and severity at that level (urethritis, cystitis, pylonephritis, or renal abscess), the age of the child (under 2 months versus over 2 months), the presence of underlying abnormalities of the genitourinary or immune system.  Consideration must also be given to whether adequate follow up can be assured and the ability to tolerate oral medications.  
  • Depending on the patient and risk factorws, consider in-clinic follow up in 48 to 72 hours to evaluate clinical response and to tailor treatment based on culture results.
    • At minimum, provide guidance to the family to follow up if not improving during this time frame and phone follow up regarding culture results and medication changes.
  • In general, if there is an adequate response to antibiotics antibiotics can be continued for
                      
    • 10 days for febrile children 
    • 3-5 days (shortened course) can be considered for afebrile, immunocompetent, otherwise well children
  • If there is an inadequate response at follow up, recommendations are to repeat new cultures and change antibiotic course according to culture speciation and sensitivities

 

Imaging

The rationale behind imaging pediatric patients with a UTI is to try to identify abnormalities of the GU tract which can predispose a child to recurrent infections, and for which there are potentially steps that can be taken to help minimize infections and subsequent renal scaring.

Examples of these anatomic defects include:

  • Vesicoureteral Reflux (VUR) due to high implantation of ureter on bladder
  • Posterior urethral valves
  • Renal dysplasia
  • Ectopic kidney
  • Duplex collecting system
  • Ureteropelvic junction obstruction
  • Ureterocele
  • Bladder diverticulum

2011 AAP Guidelines recommend an ultrasound of the bladder and kidneys for every infant 2mo-24mo who presents with a UTI. If there are any renal anormalities (hydronephrosis, scarring, anatomic abnormalities) or recurrent febrile UTIs, a VCUG may be performed. 

 

Renal ultrasound (US)

  • Safest and fastest method for detecting anomalies
  • Also useful for dx renal abscess and lobar nephronia
  • Not adequate imaging for diagnosing VUR
  • Typically performed within 2-4 weeks after diagnosis if treated outpatient or in house if admitted

Voiding cystourethrogram (VCUG)

  • Gold standard for diagnosing VUR
  • If indicated, acquire as soon and urine becomes sterile or when Abx course completed
  • Preferred over nuclear cystography

Renal scan (DMSA scintigraphy)

  • Gold standard for dx acute pyelonephritis and renal scarring
  • The diagnosis of renal scarring following resolution of acute pyelonephritis can affect future care, and should be performed 6 months after infection to allow resolution of reversible lesions

                                            

Chronic Management

In general, no long-term prophylactic antibiotics are needed if a child has normal anatomy

Prophylactic (ppx) antibiotics should be considered for patients with VUR or recurrent UTI's is area of controversy. Some recommend prophylaxis with Bactrim, Trimethoprim alone, Nitrofurantoin, cephalexin, Sulfisoxazole, Nalidixic Acid for all patients with VUR.

Surgery is indicated if failed medical management with UTIs or persistent VUR, especially with renal injury, and can be one of several procedures. It may involve injection of a bulking agent to alter ureteral insertion into the bladder, or may involve reimplantation of the ureter. 

Repeat imaging with a VCUG is indicated every 1-3 years for those with VUR on ppx to monitor for resolution of VUR

Daily preventive practices should be undertaken, including advising families to:

  • Avoid bubble baths
  • Maintain good local hygiene
  • Wipe front to back in females
  • Encourage frequent and complete voiding
  • Maintain high PO hydration

 

References

  1. Braga, L. H., Mijovic, H., Farrokhyar, F., Pemberton, J., DeMaria, J., & Lorenzo, A. J. (2013). Antibiotic prophylaxis for urinary tract infections in antenatal hydronephrosis. Pediatrics, 131(1), e251–61.
  2. Feld, L. G., & Mattoo, T. K. (2010). Urinary tract infections and vesicoureteral reflux in infants and children. Pediatrics in review / American Academy of Pediatrics, 31(11), 451–63.
  3. Finnell, S. M. E., Carroll, A. E., & Downs, S. M. (2011). Technical report—Diagnosis and management of an initial UTI in febrile infants and young children. Pediatrics, 128(3), e749–70. doi:10.1542/peds.2011-1332
  4. La Scola, C., De Mutiis, C., Hewitt, I. K., Puccio, G., Toffolo, A., Zucchetta, P., Mencarelli, F., et al. (2013). Different Guidelines for Imaging After First UTI in Febrile Infants: Yield, Cost, and Radiation. Pediatrics, 131(3), e665–71. doi:10.1542/peds.2012-0164
  5. Roberts, K. B. (2011). Urinary tract infection: clinical practice guideline for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months. Pediatrics, 128(3), 595–610. doi:10.1542/peds.2011-1330
  6. Wan, J., Skoog, S. J., Hulbert, W. C., Casale, A. J., Greenfield, S. P., Cheng, E. Y., & Peters, C. A. (2012). Section on Urology response to new Guidelines for the diagnosis and management of UTI. Pediatrics, 129(4), e1051–3. doi:10.1542/peds.2011-3615
  7. Shaikh N., et al.  Acute management, imaging, and prognosis of urinary tract infections in infants and children older than one month.  Up to Date, 2013.
  8. Shaikh N., et al.  Long-term management and prevention of urinary tract infections in children.  Up to Date, 2012.