Diagnosis and Management of UTI in Febrile Young Children

Educational Objectives

The goals of this program are to improve the diagnosis and management of urinary tract infections (UTIs) in young children. After hearing and assimilating this program, the clinician will be better able to:

1. Recognize risk factors for UTI in febrile children.

2. Prescribe effective pharmacologic therapy for children with UTI.

Summary

Importance of identifying pediatric urinary tract infection (UTI): UTI common source of fever in young children; combination of diagnosed UTI and fever often indicates pyelonephritis; children with pyelonephritis at risk for sequelae (particularly renal scarring); some evidence suggests delay in diagnosis and treatment may increase risk

Prevalence of UTI in febrile children: data from several studies suggest prevalence 4% to 8% in girls and 1% to 3% in boys ages 0 to 24 mo; effect of age in girls — risk for UTI highest during first 3 mo of life; 5% to 6% at ages 4 to 12 mo; drops significantly after age 12 mo; impact of source of fever — presence of symptoms suggesting other possible source of fever associated with lower (but not 0%) risk for UTI, compared with children with no other source

Clinical decision rule for girls age <2 yr: risk factors for UTI — age <12 mo; non-black ethnicity; temperature >39°C; fever for >2 days; no other potential source of fever; sensitivity for UTI ≈100% if ≥2 risk factors required (≈90% if ≥3 risk factors required); children with ≥3 risk factors have ≈5% risk for UTI, while those with 0 to 2 risk factors have <1% risk

Threshold for testing: study (Roberts, 1983) — found vast majority of academic pediatricians and primary care practitioners would not obtain urine culture in child if risk for UTI <1%; for children with risk 1% to 3%, ≈50% would obtain culture, and for those with risk >5%, ≈100% of participants would test for UTI

Impact of circumcision on prevalence of UTI in boys: multiple studies show being uncircumcised presents clear risk factor for UTI (in boys age <12 mo, relative risk 5-10 times greater than in circumcised infants)

Testing for UTI: methods of urine collection — include cup, bag, catheter, and suprapubic aspiration (SPA); different methods have different trade-offs in convenience, cost, efficiency, and accuracy; data suggest only ways to obtain good urine culture specimen either clean catch by toilet-trained patient or by catheter (rate of contamination in bagged specimens 12%-83% [much lower with catheter])

Definition of positive culture: SPA — suspicious if any growth; definite with >102 colony-forming units (CFU)/mL; catheter — definite if >5x104 CFU/mL of single organism; clean catch — suspicious if >105 CFU/mL in single specimen; definite if >105 CFU/mL in 2 specimens

Screening tests: options include urine dipstick (nitrite or leukocyte esterase [LE]), microscopic analysis of centrifuged urine (looking for bacteria or white blood cells [WBC]/high-power field [HPF]) or uncentrifuged urine (looking for WBC/mm3), and Gram stain (GS); performance of screening tests — GS and dipstick analysis perform similarly in detecting UTI in children (both offer high sensitivity and low rate of false-positive results); microscopic analysis of centrifuged urine neither sufficiently sensitive nor specific in young children for use as sole screening test

American Academy of Pediatrics (AAP) guidelines for evaluation of young child with fever: girls age <2 yr — urine specimen required for screening test and culture with ≥3 risk factors or past history of UTI; boys age <1 yr — urine specimen required if uncircumcised or ≥3 risk factors (speaker recommends ≥4), or past history of UTI; positive GS or nitrite dipstick analysis warrants presumptive treatment pending results of culture; if screening test completely negative (no initial evidence of pyuria), empiric treatment not necessary but urine culture still recommended; if some evidence of pyuria on LE dipstick analysis or WBC microscopy but negative for nitrites, wait for results of urine culture (consider presumptive treatment if patient at high risk for UTI)

Treatment of UTI: goals — symptomatic relief; prevention of renal scarring; factors associated with highest risk for scarring — age <1 yr (evidence mixed); underlying vesicourinary reflux; delay in treatment; candidates for inpatient therapy — recommended by speaker for infants <3 mo (up to 6 mo) of age; ill appearing and dehydrated; unable to tolerate oral medication; urologic anomalies; questionable compliance; outpatient therapy — appropriate for vast majority of children with UTI; recommended duration of treatment 7 to 14 days; initial treatment trimethoprim-sulfamethoxazole (TMP-SMX) or cephalosporin; no difference in outcomes seen with initial dose of intravenous (IV) antibiotics; based on results of urine culture, therapy may require change

Follow-up evaluation: after initial UTI, only routinely recommended test renal ultrasonography (US); if normal, no further testing needed unless UTI recurrent (if so, consider voiding cystourethrography [VCUG]); if US shows either hydronephrosis or renal scarring, VCUG recommended

Questions and Answers

Significance of clumps of WBCs on urinalysis: suggests pyuria (speaker unaware of other possible diagnoses); not shown to affect sensitivity or specificity

Age threshold for concern about UTI in circumcised boy: risk drops significantly after 3 mo of age

Collection of urine specimen into “sterile hat”: British study of method found contamination rate only slightly higher than in clean-catch specimens; however, difficult to do; catheter specimen preferred, if possible (much quicker and less likely to cause problems)

Urinalysis (UA) positive for bacteria but no GS done: bacteria by itself with negative or no GS has little significance

Negative predictive value of bag urine specimen and need for catheterization: whether bag or catheter specimen obtained, negative screening test not sufficiently sensitive to rule out need for urine culture (requires catheter specimen)

Percentage of patients with UTI who have abnormal renal scan: literature suggests 60% to 85% of children with both fever and UTI have scan showing evidence of pyelonephritis

Likelihood of having positive GS with contaminant: highly unlikely; false-positive rate of GS ≈5%; some, but very few, false-positive GS due to contaminant

Readings

Suggested Reading

Andreoli SP: Acute kidney injury in children. Pediatr Nephrol 2009 Feb;24(2):253-63; Bitsori M, Galanakis E: Pediatric urinary tract infections: diagnosis and treatment. Expert Rev Anti Infect Ther 2012 Oct;10(10):1153-64; Finnell SM et al: Subcommittee on Urinary Tract Infection. Technical report — Diagnosis and management of an initial UTI in febrile infants and young children. Pediatrics 2011 Sep;128(3):e749-70; Fortenberry JD et al: Acute kidney injury in children: an update on diagnosis and treatment. Pediatr Clin North Am 2013 Jun;60(3):669-88; Gipson DS et al: Management of childhood onset nephrotic syndrome. Pediatrics 2009 Aug;124(2):747-57; Gorelick MH et al: Validation of a decision rule identifying febrile young girls at high risk for urinary tract infection. Pediatr Emerg Care 2003 Jun;19(3):162-4; Habib S: Highlights for management of a child with a urinary tract infection. Int J Pediatr 2012;2012:943653. doi: 10.1155/2012/943653. Epub 2012 Jul 19; Hoberman A, Keren R: Antimicrobial prophylaxis for urinary tract infection in children. N Engl J Med 2009 Oct 29;361(18):1804-6; Kambham N: Postinfectious glomerulonephritis. Adv Anat Pathol 2012 Sep;19(5):338-47; Keir LS et al: Shigatoxin-associated hemolytic uremic syndrome: current molecular mechanisms and future therapies. Drug Des Devel Ther 2012;6:195-208; Lombel RM et al: Kidney Disease: Improving Global Outcomes. Treatment of steroid-sensitive nephrotic syndrome: new guidelines from KDIGO. Pediatr Nephrol 2013 Mar;28(3):415-26; Misurac JM et al: Nonsteroidal anti-inflammatory drugs are an important cause of acute kidney injury in children. J Pediatr 2013 Jun;162(6):1153-9, 1159.e1; Nester CM: Multifaceted hemolytic uremic syndrome in pediatrics. Blood Purif 2013;35(1-3):86-92; Roberts KB et al: 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 2011 Sep;128(3):595-610; Rodriguez-Iturbe B, Musser JM: The current state of poststreptococcal glomerulonephritis. J Am Soc Nephrol 2008 Oct;19(10):1855-64; Shaikh N et al: Risk of renal scarring in children with a first urinary tract infection: a systematic review. Pediatrics 2010 Dec;126(6):1084-91; Singh D et al: Emergency management of hypertension in children. Int J Nephrol 2012;2012:420247. doi: 10.1155/2012/420247. Epub 2012 Apr 19; Tran CL et al: Recent trends in healthcare utilization among children and adolescents with hypertension in the United States. Hypertension 2012 Aug;60(2):296-302; Williams GJ et al: Diagnosis and management of urinary tract infection in children. J Paediatr Child Health 2012 Apr;48(4):296-301; Zorc JJ et al: Multicenter RSV-SBI Study Group of the Pediatric Emergency Medicine Collaborative Research Committee of the American Academy of Pediatrics. Clinical and demographic factors associated with urinary tract infection in young febrile infants. Pediatrics 2005 Sep;116(3):644-8.

Disclosures

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, members of the faculty and planning committee reported nothing to disclose. In his lecture, Dr. Gorelick presents information that is related to the off-label or investigational use of a therapy, product, or device.

Acknowledgements

Dr. Gorelick spoke at the 14th Annual Pediatric Emergency Medicine meeting, held April 3-6, 2013, in Lake Buena Vista, FL, and presented by the Nemours Alfred I. DuPont Hospital for Children and Jefferson Medical College. To learn about future CME activities at Nemours, please visit their website at www.pedsuniversity.org. The Audio-Digest Foundation thanks Dr. Gorelick, the Nemours Alfred I. DuPont Hospital for Children, and Jefferson Medical College for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

PD600101

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.

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