URINARY TRACT INFECTION IN INFANTS AND YOUNG CHILDREN: An Evidence Based Review of Diagnosis and Management (Andi Marmor, M.D.)

Physicians at California Pacific’s Pediatric Specialty Services have developed treatment pathways for common clinical areas. Each of these pathways is evidence-based and collaboratively developed with our hospitalists, specialists and primary care physicians, along with nursing and ancillary staff. The pathways reflect a national trend towards developing clinical guidelines in pediatrics. Following are treatment recommendations from our urinary tract infection pathways.

Question 1: Which infants/children should be tested for UTI?
Recommendations:
1. Consider UTI in all infants and children with FWS (for 1-3 month T>38.5, for > 3 months T>39)

2. In general:
Girls: All girls less than 24 months of age with FWS should be tested for UTI
Boys: Uncircumcised boys with FWS less than 6-12 mo of age
Circumcised boys with FWS less than 3-6 mo of age

Question 2: What tests are most useful for diagnosing a UTI?
Recommendations:
1. Positive UA results:
a. LE alone has a significant risk of false positives (~70%) so a confirmatory culture should be sent.
b. Nitrite alone is fairly specific (false positives less likely) so empiric treatment may be started. A confirmatory culture is still recommended in this
c. Micro: high # WBC’s increase probability of UTI
d. Multiple positive tests increase positive predictive value

2. Negative UA results:
a. If prior probability is LOW, a negative result is unlikely to be false negative – probably OK to skip the culture
b. In very young infants, and others with higher prior probability of UTI, false negatives are more likely so a confirmatory culture of a catheter specimen should be sent

Question 3: How should urine be obtained for testing for a UTI?
Recommendations:
1. In very high risk infants (<3 months of age, uncircumcised boy) or a child who looks sick enough to require IV antibiotics, obtain a catheter specimen for urinalysis and culture

2. In other children, if obtain a specimen by the most convenient method and send for UA
a. If the UA is negative, the specimen can probably be discarded, unless the prior probability of UTI is high (thereby increasing false negative rate)
b. If the UA is positive, obtain a catheter sample to send for culture

Question 4: How and why should we treat a UTI?
Recommendations:
1. Prompt treatment of UTI’s is recommended in infants and children, especially in those at high risk for or with documented urinary tract abnormalities

2. Admit for IV antibiotics if toxic-appearing, younger than 3 months of age, unable to tolerate po’s, questionable compliance with meds and follow up.

3. Outpatient therapy is likely to be effective in older and well-appearing children
-Keflex a good first-line choice for local sensitivities
-Give first dose of antibiotics IM/IV or observe PO in clinic
-10-14 days of therapy recommended

4. Follow up is essential: if patient does not respond as expected, consider admission for IV therapy and further workup.

Question 5: What sort of imaging and is needed for a child with a UTI?
Recommendations:
1. Choice of imaging strategy should take into account the prior probability of obstruction, the consequences of false positive and false negative results, as well as parental and physician preference

2. Strongly consider a renal ultrasound (if no 3rd trimester prenatal US) to look for obstruction, renal system abnormalities or high grade VUR in:
a. Very young or very sick infants
b. After 1st UTI in circumcised boys <1 yr
c. After 1 or more UTI’s in uncirc boys, girls and circ boys under 2

3. Follow up:
a. If ultrasound shows hi grade VUR or obstruction, obtain VCUG, consider prophylactic antibiotics, and definitely increase surveillance for febrile illnesses
b. Regardless of imaging results, diagnose and treat UTI recurrences promptly
c. Consider VCUG in children with recurrent or severe UTIs, or if no improvement after 48 hours of treatment (recommendations are to delay VCUG for 3-4 days after initiation of therapy)

Clarifications:
1. Who should get UA and cx: and how:
a. Fever Without Source less then 36 month: (see age and gender and circumcision reccs)
b. under 3 mo always send urine cx even if negative UA
c. For positive bag UA’s:
i. Cath for culture if < 1 year
ii. Consider bag cx if > 1 year and clean sample

2. Treatment:
a. Less then 2 months admit IV abx (Amp and gent or Ceftriaxone if applicable)
b. 2-3 months: Consider admission: rx w. IV or IM

3. Imaging: Inpatient (out patient follow above recommendations)
a. VCUG: can be done 3-4 days after start of antibiotics if evidence of renal US or high risk.
b. Renal ultra sound: consider doing as inpatient if:
i. Less then 3 month
ii. High risk for VUR or chronic hx.

4. Prophylaxis antibiotics: Consider if:
a. Positive imaging studies.
b. If planning on doing VCUG as out patient.

5. Length of stay in hospital for documented UTI (positive cx)
a. If afebrile >24hrs d/c on Keflex PO (if unknown sensitivities ) or appropriate abx with final ID.
b. If still febrile 48-72 hrs on antibiotics consider:
i. Repeat UA and cx
ii. Renal US
iii. Changing to Ampicillin and Gentamicin
iv. Cbc and blood cx

REFERENCES
1. Al-Orifi F, et al. Urine culture from bag specimens in young children: are the risks too high? J Pediatr 2000 Aug; 137(2): 221-226 (abstract only)
2. American Academy of Pediatrics Committee on Quality Improvement. Practice parameter: The diagnosis, treatment and evaluation of the initial urinary tract infection in febrile infants and young children. Pediatrics April 1999; 103(4): 843-852
3. American Academy of Pediatrics Committee on Quality Improvement. Technical report: Urinary tract infection in febrile infants and young children. Pediatrics April 1999; 103(4): e54
4. Bachur R, Harper MB. Reliability of the urinalysis for predicting urinary tract infections in young febrile children. Arch Ped Adolesc Med Jan 2001; 155: 60-65
5. Gorelick MH, et al. Screening tests for urinary tract infection in children: A meta-analysis. Pediatrics 1999 Nov; 104(5): e54
6. Hoberman A, et al. Oral versus initial intravenous therapy for urinary tract infections in young febrile children. Pediatrics 1999; 104:79-86
7. Hoberman A, et al. Imaging studies after a first febrile urinary tract infection in young children. NEJM Jan 2003; 348(3): 195-202
8. Huicho L, et al. Metanalysis of urine screening tests for determining the risk of urinary tract infection in children. Ped Infect J 2002; 21(1): 1-11
9. Jodal U, et al. Infection pattern in children with vesicoureteral reflux randomly allocated to operation or long-term antibacterial prohylaxis. The International Reflux Study in Children. J Urol 1992; 148: 1650-52
10. Keren R, Chan E. A meta-analysis of randomized, controlled trials comparing short- and long-course antibiotic therapy for urinary tract infections in children. Peciatrics May 2002; 109(5): e70
11. Kramer MS, et al. Urine testing in young febrile children: A risk-benefit analysis. J Pediatr 1994 July; 125(1): 6-13 (abstract)
12. Lin D, et al. Urinary tract infection in febrile infants younger than eight weeks of age. Pediatrics Feb 2000; 105(2): e20
13. Newman TB, et al. Urine testing and urinary tract infections in febrile infants seen in office settings. Arch Ped Adol Med Jan 2002; 156: 44-54
314. Shaw KN, et al. Screening for urinary tract infection in infants in the emergency department: Which test is best? Pediatrics 1998 Jun; 101(6):e1 (abstract only)
15. Weiss R, et al. Results of a randomized clinical trial of medical versus surgical management of infants and children with grades III and IV primary vesicoureteral reflux. The International Reflux Study in Children. J Urol 1992; 148: 1667-73

For questions, please contact:
Oded Herbsman M.D.
Medical Director Pediatric Unit
California Pacific Medical Center
2340 Clay Street, 3rd floor
San Francisco, CA 94115
Pager: 415-998-0323
E mail: herbsmo@sutterhealth.org

Coming next month in the Pediatric Page: Evaluation and Management of Hypertension in Children

Visit our Pediatric Specialty Services web site at www.cpmc.org/advanced/pediatrics