Pediatric Infectious Diseases - Urinary Tract Infections

Question 1

What are the risk factors for a UTI in febrile infants?

Answer 1

Girls: White race, Age <12 months, Temperature ≥39oC, Fever ≥ 2 days, Absence of another source of infection
Boys: Nonblack race, Temperature ≥39oC, Fever ≥ 24 hours, Uncircumcised, Absence of another source of infection

Question 2

What is the pathogenesis of a UTI?

Answer 2

Retrograde ascent (up the urethra)
Nosocomial infection
Hematogenous spread
Fistula formation

Question 3

What are the causative pathogens of UTIs?

Answer 3

escherichia coli!!

Question 4

What are the signs/sypmtoms of UTIs?

Answer 4

Evaluate all febrile children <24 months
Older children should be evaluated if clinical presentation points to urinary source
Signs and symptoms vary by age

Question 5

What are the signs/sypmtoms of UTIs in newborns?

Answer 5

Jaundice
Sepsis
Failure to thrive
Vomiting
Fever

Question 6

What are the signs/sypmtoms of UTIs in infants/young children?

Answer 6

Fever
Strong-smelling urine
Hematuria
Abdominal/flank pain
New-onset urinary incontinence

Question 7

What are the signs/sypmtoms of UTIs in school-aged children?

Answer 7

Symptoms similar to adults including: Dysuria, Frequency, Urgency

Question 8

What are the methods of urine collection?

Answer 8

Clean catch
◦ Older patient groups
Catheterization!
◦ Preferred for <24 month age group!!!
Supra-pubic aspiration (SPA)
◦ Gold-standard, but invasive (usually reserved for young children who fail catheterization)
Bag specimen not recommended
◦ Unacceptably high rates of false-positive cultures

Question 9

What is a urinalysis?

Answer 9

Performed with culture
Test urinalysis on any “fresh” urine specimen
◦ <1 hour after voiding if room temperature
◦ <4 hours after voiding if refrigerated

Question 10

What is a urine dipstick?

Answer 10

Yields rapid results
Leukocyte esterase
◦ Suggests inflammation and presence of WBCs
◦ More sensitive, less specific: False positive common
◦ Absence of leukocyte esterase in asymptomatic bacteriuria is an advantage
◦ Separates asymptomatic bacteriuria from true UTI
Nitrite
◦ Less sensitive, more specific
◦ False positive uncommon
◦ Converted from dietary nitrates in presence of most gram-negative enteric bacteria
in urine
◦ Process takes ~4 hours; babies empty bladders more frequently

Question 11

What is a urine microscopy?

Answer 11

More expensive
Evaluates WBCs, RBCs, and bacteria in sample
Pyuria = >5-10 WBCs per μL
Bacteruria = any bacterial per μL

Question 12

What if nitrite and leukocyte esterase are both negative on a urine dipstick?

Answer 12

100% predictive

Question 13

What is a urine culture?

Answer 13

SPA: >10,000 CF/mL
Catheter specimen: >10,000 CFU/mL
Clean catch: >100,000 CFU/mL
Obtain cultures and urinalysis before starting antibiotics whenever possible!

Question 14

What is the treatment for UTIs?

Answer 14

Oral and IV equally efficacious
Most patients can have oral therapy
Choose IV for patients who are:
◦ “Toxic”
◦ Unable to retain oral intake
Can change to oral therapy when patient has clinical improvement – usually within 24-48 hours

Question 15

What is the duration of treatment for UTIs?

Answer 15

Controversial
◦ 7-14 days for ages 2-24 months
◦ 10-14 days for pyelonephritis
◦ 3-7 days for cystitis in older female patients
◦ Single day therapy inferior in children
Older children may be able to get by with a 3 day course of therapy (girls)

Question 16

What are the treatment options for UTIs?

Answer 16

cephalexin, amoxicillin (traditionally 1st line!), amoxicillin-clavulanate, SMX/TMP
NOT nitrofurantoin, this is only used in cystitis

Question 17

Fluoroquinolones in children

Answer 17

Traditionally not used in children; resistance = major concern
May be useful in some circumstances
◦ Multidrug-resistant pathogens with no safe alternative; IV therapy is not feasible; No other effective oral agent
AAP guidelines recommend FQ use for Pseudomonas or other multidrug- resistant gram-negative bacteria
Peds pearls:
◦ Don’t give cipro suspension through a feeding tube – will clog!
◦ Quinolone liquids often require PAs

Question 18

What is the follow-up for UTIs?

Answer 18

Considerations for renal/bladder ultrasound and voiding cystography: All boys; All girls < 3 years of age; Girls 3-7 years with fever > 38.5 degC
◦ AAP recommends only ultrasound for 2-24 months of age

Question 19

What are strategies to prevent UTIs?

Answer 19

Efficacy of prophylaxis is questionable
Some clinicians perceive benefit in children with vesicoureteral reflux (VUR) - No benefit found in mild to moderate, Some benefit with severe VUR
Continuous prophylaxis may not reduce risk of pyelonephritis or renal damage
Cranberry juice?