Urinary tract infection in infants and children: Diagnosis and management

Question 1

What percentage of children 2-24mo with fever without a source were diagnosed with UTI?

Answer 1

7%

Question 2

What percentage of children 2-19yo with possible urinary symptoms were diagnosed with UTI?

Answer 2

8%

Question 3

What is the rate of UTI in uncircumcised febrile boys <3mo?

Answer 3

20.7%

Question 4

What is the rate of UTI in circumcised febrile boys <3mo?

Answer 4

2.4%

Question 5

What is the rate of UTI in uncircumcised febrile boys 6-12mo?

Answer 5

7.3%

Question 6

What is the rate of UTI in circumcised febrile boys 6-12mo?

Answer 6

0.3%

Question 7

What is the rate of UTI in febrile girls <3mo?

Answer 7

7.5%

Question 8

What is the rate of UTI in febrile girls 3-6mo?

Answer 8

5.7%

Question 9

What is the rate of UTI in febrile girls 6-12mo?

Answer 9

8.3%

Question 10

What is the rate of UTI in febrile girls 12-24mo?

Answer 10

2.1%

Question 11

When should a urinanlysis and urine culture be obtained?

Answer 11

Children <3yo with a fever (>39 degrees rectal) with no apparent source

Children >3yo with urinary symptoms

Question 12

Should febrile children 2mo-3yo with rhinitis, cough, wheeze, rash, or diarrhea need to be investigated for UTI?

Answer 12

No

Question 13

What features predispose girls to URI?

Answer 13

1. <12mo
2. White race
3. Temperature >39
4. Fever >2d
5. Absence of another source of fever

Children with no more than one of these features have <1% risk of UTI

Question 14

What is the contamination rate of bag samples?

Answer 14

63%

Question 15

What are recommended methods of obtaining urine samples from non-toilet trained children?

Answer 15

1. Urethral catheterization
2. Suprapubic aspiration
3. Leaving the diaper off and obtaining a clean-catch urine when child voids

Question 16

What is the recommended method of obtaining urine samples from a toilet trained child?

Answer 16

Clean catch

Question 17

What is the specificity and specificity of components of the urinanalysis in predicting UTI?

Answer 17

1. Leukocyte esterase (LE) 83% sens 76% spec
2. Nitrites (NT) 53% sens 98% spec
3. Either LE or NT positive 93% sens 72% spec
4. Microscopy WBC 73% sens 81% spec
5. Microscopy bacteria 81% sens 83% spec
6. LE, NT, or microscopy positive 99.8% sens 70% spec

Question 18

What are the minimum colony counts that are indicative of a UTI?

Answer 18

1. Clean catch >10^5 CFU/mL or >10^8 CFU/L
2. In and out catheter specimen >5x10^4 CFU/mL or >5x10^7 CFU/L

Mixed growth = contamination

3. Suprapubic aspiration any growth

Question 19

When should blood cultures be drawn in a child with a UTI?

Answer 19

If child is hemodynamically unstable

Question 20

When should renal function be monitored in a child with UTI?

Answer 20

Complicated UTI

Treatment with aminoglycosides >48h

Question 21

What is the recommended empiric treatment for febrile UTI in non-toxic children with no structural urological abnormalities?

Answer 21

Cefixime PO x 10-14d

Question 22

What is the recommended empiric therapy for febrile UTI in hospitalized children?

Answer 22

IV gentamicin +/- IV ampicillin

Consider cefotaxime or ceftriaxone due to nephrotoxicity of gentamicin

Question 23

What is the recommended empiric therapy for non-febrile UTI (cystitis) with urinary symptoms?

Answer 23

PO antibiotics x 2-4d cover E coli

Question 24

When to be concerned that a child has complicated UTI?

Answer 24

1. Hemodynamically unstable
2. Elevated serum Cr level
3. Bladder or abdominal mass
4. Poor urine flow
5. Not improving clinically within 24h
6. Fever not trending down within 48h of antibiotics

Question 25

What are the recommendations for complicated UTI?

Answer 25

US to r/o obstruction or abscess

IV antibiotics

Question 26

What should one do if a multiresistant organism is isolated in urine?

Answer 26

May use quinolones if organism is resistant to all other oral antibiotics
If clinical improvement and patient asymptomatic consider repeating urine culture and not changing antibiotics

Question 27

What parenteral antibiotics are commonly used to treat UTIs in children >2mo if isolate is susceptible?

Answer 27

Ampicillin IV
Ceftriaxone IV/IM
Cefotaxime IV/IM
Gentamicin IV/IM
Tobramycin IV

Question 28

What oral antibiotics are commonly used to treat UTIs in children >2mo if isolate is susceptible?

Answer 28

Amoxicillin
Amoxi-clav
SMX/TMP
Cefixime
Cefprozil
Cephalexin
Ciprofloxacin

Question 29

When should a RBUS be performed?

Answer 29

US in <2yo with first febrile UTI within 2wks of acute illness

Question 30

When should VCUG be obtained?

Answer 30

1. <2yo with second well-documented UTI

2. RBUS suggestive of selected renal abnormalities, obstruction, or high grade VUR

Question 31

When can a nuclear cystogram (NCG) be used?

Answer 31

In place of VCUG in initial test for females and in follow-up studies for both sexes

Question 32

What will nuclear cystograms (NCG) miss?

Answer 32

Posterior urethral valves

Question 33

When can a DMSA scan be used?

Answer 33

Diagnose acute pyelonephritis and to identify renal scars

Question 34

What are the recommendations regarding UTI?

Answer 34

1. 2-36mo with fever >39°C and no other source should have urine collected by catheter or suprapubic aspirate sent for culture. May use bag urinalysis to screen.
2. In toilet trained child use midstream urine for R&M and C&S.
3. Children with possible UTI who require antibiotic treatment immediately for other indications, such as suspected bacteremia, should have urine collected for urinalysis, microscopy and culture. The test sample should be midstream urine if the child is toilet trained, and a catheter or SPA or clean-catch specimen if not, and obtained before starting antibiotics.
4. Overdiagnosis of UTI is a common problem, leading to overuse of antibiotics and unnecessary imaging.
5. Urines collected by bag should never be used for diagnosis of UTI. Urines with low colony counts, mixed growth or no pyuria are usually contaminated.
6. Infants and children with febrile UTI should be treated with antibiotics for seven to 10 days. Oral antibiotics can be administered as initial treatment when the child has no other indication for admission to hospital and is considered likely to receive and tolerate every dose.
7. There is no evidence that children with UTIs and documented bacteremia who have a rapid clinical response to antibiotics require intravenous antibiotics or a longer course of antibiotics. However, all such children need to be assessed by a physician the day that the blood culture is known to be positive. The choice of antibiotic should be guided by the resistance pattern of common urinary pathogens in the community and changed to a less broad spectrum agent, if practical, when the sensitivity of the pathogen is known.
8. Children <2 years of age should be investigated after their first febrile UTI with a renal and bladder ultrasound (RBUS) to identify significant renal abnormalities and grade IV or V VUR. A voiding cystourethrogram (VCUG) is not indicated with a first febrile UTI when the RBUS is normal.
9. Antibiotic prophylaxis is no longer recommended for grades I through III VUR or pending results of the initial RBUS.
10. Children with grade IV or V VUR or a significantly abnormal RBUS should be discussed with a paediatric urologist or nephrologist to determine whether there is an urgent need for a consult and make the best plan for further investigation and management.
11. Parents of all children with febrile UTIs, with or without VUR, should be advised that their child needs to be assessed for the possibility of recurrent UTI early in the course of any unexplained fever. Such guidance is especially pertinent in this era, where very few children are on prophylactic antibiotics for UTIs.
12. For older children with no fever and presumed cystitis, a two- to four-day course of oral antibiotics is usually adequate.

Question 35

What future research is needed for optimal management of UTI in children?

Answer 35

1. Long-term cohort studies to establish the relationship between UTI in infants and young children and reduced renal function and hypertension in adults.
2. Less invasive techniques for diagnosis of VUR and better understanding of the contribution of VUR and other risk factors to the development of renal function abnormalities.
3. Assessment of optimal treatment strategies (length of therapy, choice of antibiotics) for febrile UTIs and for older children with cystitis.
4. Management strategies for infants <2 months of age with UTIs