Transcript Pediatrics Urinary Tract Infections

Pediatric Urinary Tract
Infections
Dr.Fahad Gadi, MD
Pediatrics Demonstrator
King Abdulaziz University
Rabigh Medical School
Objectives




Define Urinary Tract Infection (UTI)
List antibiotic treatment options for UTI
List the workup after a first febrile UTI
Be familiar with the rationale for using
prophylactic antibiotics after the first febrile
UTI
Pediatric UTIs and EBM


Up to 7% of girls and 2% of boys experience a
symptomatic culture-proven UTI prior to 6
years of age.
Of febrile neonates, up to 7% have UTIs.


(See Fever without a source guidelines)
Most UTIs in children are from ascending
bacteria

E. coli (60-80%), Proteus, Klebsiella, Enterococcus,
and coag. neg. staph.
Epidemiology




The overall prevalence of UTI is approximately 5
percent in febrile infants but varies widely by race and
sex.
Caucasian children had a two- to fourfold higher
prevalence of UTI as compared to African-American
children
Females have a two- to fourfold higher prevalence of
UTI than do circumcised males
Caucasian females with a temperature of 39 ºC have a
UTI prevalence of 16 percent
Approximate probability of urinary tract infection
in febrile infants and young children by
demographic group
Demographic group
Prevalence (pretest
probability)
Odds
Circumcised boys >1 yr
<1 percent
.01 (1 in 100)
Circumcised boys <1 yr
2 percent
.02 (1 in 50)
Black girls
Uncircumcised boys <2
yr
4 percent
.04 (1 in 25)
8 percent
.09 (1 in 12)
White girls <2 yr
16 percent
.19 (1 in 5)
Definition of UTI on culture
Method of urine collection
Diagnostic threshold
Clean-catch in voiding girls
100,000 CFU per mL
10,000 – 100,000  repeat culture
Clean-catch in voiding boys
10,000 CFU per mL
Catheter
10,000 CFU
1,000 – 10,000  repeat culture
Suprapubic aspiration
Any colonies of GNRs
More than a few thousand GPCs
Symptoms

Classic UTI symptoms in older children


Dysuria, frequency, urgency, small-volume voids,
lower abdominal pain.
Infants with UTIs have nonspecific symptoms

Fever, irritability, vomiting, poor appetite
Neonatal hematuria?
Nope, it’s uric acid crystals
Evaluation




In children with a high likelihood of UTI, a
urine culture is required.
In children with a low likelihood, a negative
dipstick in a clear urine reduces the need for
culture.
If the dipstick shows (+) LE and/or (+)
Nitrites, send a urine culture.
The dipstick is not sufficient to diagnose UTI’s
because false positives can occur.
Urine dipsticks

In a cohort study with an 18% baseline
prevalence of UTI, negative LE and nitrates on
dipstick had a negative predictive value of 96%.

NPV =
True negative
_________________
True negative + false negative
Leukocyte Esterase and Nitrites

LE is produced from the breakdown of
leukocytes. Not always indicative of infection


Vaginitis/vulvitis can lead to inflammation without
infection  + LE
Nitrites are produced by bacteria that metabolize
nitrates: E. coli, Klebsiella, Proteus (GNRs)
Much more predictive of UTI
 GPCs do not produce nitrites

Blood cultures



Blood cultures are generally unnecessary in most
children with UTI.
They are more frequently positive in children
younger than two months whose urine grows
Group B strep or Staph. Aureus.
In general, we’ll send febrile children less than
two months old to the ER for emergent
evaluation/labs.
Treatment of UTIs


The efficacy of oral regimens is as effective as
parenteral regimens - this is great news for
outpatient therapy 
If the child is not responding the empiric
treatment within two days while awaiting culture
results, repeat the urine culture and perform a
renal ultrasound.
Antibiotic Choices


Trimethoprim-sulfamethoxizole is a good choice
after two months of life
Other choices:
Amoxicillin – some resistance with E. coli
 Cephalosporins: cefixime (Suprax), cefpodoxime
(Vantin), cefprozil (Cefzil), loracarbef (Lorabid)



No cephalosporins cover enterococcus
Treat for 7-14 days. One day course not
effective.
Further testing/work-up

After the UTI resolves, what type of workup
should ensue?
Vesicoureteral Reflux and
Treatment




Approximately 40% of children with febrile UTIs have
VUR.
Approximately 8% of children with febrile UTIs
demonstrate renal scarring when studied.
Treatment recommendations are made to stop the
progression of VUR with medications/antibiotics
and/or surgery.
No data/EBM demonstrate that treatment of VUR
prevents renal scarring, hypertension and CKD
Antibiotic prophylaxis

Children with VUR are treated prophylactically
with antibiotics to prevent potential renal
scarring.
Nitrofurantoin or trimethoprim-sulfamethoxizole
 Half the standard dose administered at bedtime


Family physicians would generally have a
pediatric urologist involved to assist in making
treatment decisions.
How long to continue Abx?



Although the evidence is not conclusive, it appears the
risk of scarring diminishes with age.
Accordingly, some experts recommend cessation of
prophylaxis after age 5 to 7 years, even if low-grade
VUR persists.
In one study of 51 low-risk (no voiding abnormalities
or renal scarring) older children (mean age 8.6 years)
with grades I to IV VUR, cessation of prophylactic
antibiotics resulted in no new renal scarring on annual
DMSA
Indications to order radiologic
studies





Children younger than 5 years of age with a
febrile UTI
Girls younger than 3 years of age with a first
UTI
Males of any age with a first UTI (PUV)
Children with recurrent UTI
Children with UTI who do not respond
promptly to therapy
Studies to consider

Renal Ultrasound
Will evaluate for perinephric abscess in patients not
responding to antibiotics.
 Can evaluate for hydronephrosis/hydroureter
 Of note, dilation of the kidneys and ureters can
easily be seen on routine anatomy scans during
pregnancy.
 Picking up vesicoureteral reflux while asymptomatic


Does this help or hurt? Staging of VUR, antibiotics, etc...
Hydronephrosis
Male with the findings below.
Cause?
Studies to consider

Voiding cystourethrogram – two techniques
One involves fluoroscopic contrast – more radiation
but better delineation of anatomy for grading VUR
 The other uses a radionuclide – less radiation and
more sensitive than contrast

Normal VCUG
Vesicoureteral reflux (VUR)
Megaureter
Studies to consider

Renal scintigraphy using dimercaptosuccinic acid
(DMSA)
Can detect scarring in the kidneys.
 Renal cells take up the tracer.
 Those cells damaged by pyelonephritis or scarring
do not take up the tracer.
 Management or followup of patients does not
change in most cases.
 Thus, not generally used for initial evaluation.

Scar in the
superior and
inferior pole of
the right
kidney
Myths



Bathing in bubble baths causes UTIs
Wiping back-to-front causes UTIs
Cranberry juice helps UTIs – only proven to be
of minimal benefit in adult women. No proven
benefit to children
VUR Treatment



Children 6 years or older with unilateral grade III to IV reflux
without renal scarring can be treated medically. If the reflux is
bilateral and/or there is renal scarring, surgical treatment is
recommended.
Children 6 years or older with grade V reflux should be treated
surgically with or without evidence of renal scarring, as their
reflux is unlikely to resolve spontaneously.
Surgery also should be considered if medical therapy fails either
because of poor compliance, breakthrough infections on account
of antibiotic resistance, or significant antibiotic side effects.
Finally, consideration of patient and parent preference is
important in the final decision.
Objectives




Define Urinary Tract Infection (UTI)
 >100,000 CFU in clean catch girls
 >10,000 CFU clean catch guys
 >10,000 catheter specimen
List antibiotic treatment options for UTI
 Amoxicillin, Bactrim, Cephalosporins
List the workup after a first febrile UTI
 Consider renal U/S and VCUG
Be familiar with the rationale for using prophylactic antibiotics
after the first febrile UTI

Prevent renal complications/scarring/pyelonephritis