DR Badi AlEnazi
Consultant pediatric endocrinology and
• Urinary tract infection (UTI) is one of the most common pediatric
infections. It distresses the child, concerns the parents, and may cause
permanent kidney damage. Prompt diagnosis and effective treatment of
a febrile UTI may prevent acute discomfort and, in patients with
recurrent infections, kidney damage.
The incidence of UTIs varies based on age, sex, and gender.
It was found that the overall prevalence of UTI in infants presenting
with fever was 7.0%.
the rates in girls were as follows:
 0-3 months - 7.5%
 3-6 months - 5.7%
 6-12 months - 8.3%
 >12 months - 2.1%
In febrile boys less than 3 months of age:
 2.4% of circumcised boys .
 20.1% of uncircumcised boys .
The 2 broad clinical categories of UTI are:
pyelonephritis (upper UTI)
cystitis (lower UTI).
Bacterial infections are the most common cause of UTI, with E
coli being the most frequent pathogen, causing 75-90% of UTIs.
Other bacterial sources of UTI include the following:
•Klebsiella species
•Proteus species
•Enterococcus species
•Streptococcus group B, especially among neonates
•Pseudomonas aeruginosa
•Fungi (Candida species) may also cause UTIs
•Adenovirus is a rare cause of UTI and may cause hemorrhagic
Risk factors
Susceptibility to UTI may be increased by any of the following factors:
Alteration of the periurethral flora by antibiotic therapy
Anatomic anomaly
Bowel and bladder dysfunction
Circumcision and UTI
• For male infants, neonatal circumcision substantially
decreases the risk of UTI. It was found that during the
first year of life, the rate of UTI was 2.15% in
uncircumcised boys, versus 0.22% in circumcised
boys. Risk is particularly high during the first 3 months
of life.
The American Academy of Pediatrics (AAP) criteria for the diagnosis of
UTI in children 2-24 months:
 are the presence of pyuria and/or bacteriuria on urinalysis and of at
least 50,000 colony-forming units (CFU) per mL of a uropathogen from
the quantitative culture of a properly collected urine specimen.
Urine specimen collection
• A midstream, clean-catch specimen may be
obtained from children who have urinary control.
In the infant or child unable to void on request,
the specimen for culture should be obtained
by suprapubic
aspiration or
• Suprapubic aspiration is also the method of choice for
obtaining urine from uncircumcised boys,from girls
with tight labial adhesions, and from children of either
sex with clinically significant periurethral irritation.
• Culture of a urine specimen from a sterile bag attached
to the perineal area has a false-positive rate so high
that this method of urine collection is not suitable for
diagnosing UTI. However, a culture of a urine specimen
from a sterile bag that shows no growth is strong
evidence that UTI is absent.
• Urinalysis alone is not sufficient for diagnosing UTI.
Children with unexplained fever or voiding symptoms
may have positive urinary cultures even when
abnormal findings are not evident on complete
Blood studies
• Hematologic studies do not tend to help in the diagnosis of UTIs,
although they should be obtained in patients who appear ill. Obtain a
complete blood count (CBC) and basic metabolic panel for children with
a presumptive diagnosis of pyelonephritis. Perform blood cultures in
febrile infants and older patients who are clinically ill, toxic, or severely
Evaluation of renal function
• Renal function can be measured by serum
creatinine and blood urea nitrogen (BUN) levels;
both may be elevated in severe disease. Electrolyte
abnormalities may be present.
Urinary ultrasonography is useful in:
excluding obstructive uropathy
identifying a solitary or ectopic kidney
moderate renal damage caused by pyelonephritis.
Performance of voiding cystourethrography (VCUG)
after a first febrile UTI may be indicated if:
 renal and bladder ultrasonography reveal hydronephrosis,
scarring, obstructive uropathy, or masses
complex medical conditions are associated with the UTI.
• Children who respond to treatment for a UTI but
afterwards demonstrate an abnormal voiding pattern
may need to undergo an evaluation for voiding
dysfunction. This evaluation may include standard
• VCUG is also recommended after a second episode of
febrile UTI. There is some concern, however, that
without VCUG after the first documented febrile UTI,
some cases of significant reflux disease will be missed
Children aged 0-2 months
usually do not have symptoms localized to the urinary tract. UTI is
discovered as part of an evaluation for neonatal sepsis.
Neonates with UTI may display the following symptoms:
 Jaundice
 Fever
 Failure to thrive
 Poor feeding
 Vomiting
 Irritability
Infants and children aged 2 months to 2 years
Infants with UTI may display the following symptoms:
Poor feeding
Strong-smelling urine
Abdominal pain
Children aged 2-6 years
Preschoolers with UTI can display the following
Abdominal pain
Strong-smelling urine
Urinary symptoms (dysuria, urgency, frequency)
Children older than 6 years and adolescents
School-aged children with UTI can display the following
Vomiting, abdominal pain
Flank/back pain
Strong-smelling urine
Urinary symptoms (dysuria, urgency, frequency)
Physical Examination
Costovertebral angle tenderness
Abdominal tenderness to palpation
Suprapubic tenderness to palpation
Palpable bladder
Dribbling, poor stream, or straining to void
Examine the external genitalia for signs of irritation, pinworms, vaginitis,
Differential diagnosis
Conditions that can produce the symptoms of urinary
tract infection (UTI) include the following:
Bladder and bowel dysfunction
Criteria of Hospital Admission
Usual indications for hospitalization and/or parenteral therapy include:
 Age <2 months
 Clinical urosepsis (eg, toxic appearance, hypotension, poor capillary
 Immunocompromised patient
 Vomiting or inability to tolerate oral medication
 Lack of adequate outpatient follow-up (eg, no telephone, live far from
hospital, etc)
 Failure to respond to outpatient therapy
Empiric therapy
• Early and aggressive antibiotic therapy (eg, within 72
hours of presentation) is necessary to prevent renal
damage. Delayed therapy has been associated with
increased severity of infection and greater likelihood of
renal damage .Decisions regarding the initiation of
empiric antimicrobial therapy for UTI are best made on
a case-by-case basis based upon the probability of UTI,
which is determined by demographic and clinical
We suggest that empiric antimicrobial therapy be initiated
immediately after appropriate urine collection in children with
suspected UTI and a positive urinalysis. This is particularly true for
children who are at increased risk for renal scarring if UTI is not
promptly treated, including children who present with:
•Fever (especially >39°C [102.2°F] or >48 hours)
•Ill appearance
•Costovertebral angle tenderness
•Known immune deficiency
•Known urologic abnormality
parenteral antibiotic therapy
The diagnosis in infant with a febrile UTI is usually based on fever
and on positive results from a urine specimen obtained by
catheterization. Infants with such findings are usually hospitalized
and receive parenteral antibiotic therapy
Dosage and Route
50-75 mg/kg/day IV/IM as a Do not use in infants < 6 wk
single dose or divided q12h of age; parenteral antibiotic
with long half-life; may
displace bilirubin from
150 mg/kg/day IV/IM
divided q6-8h
Note: IM = intramuscular; IV = intravenous; q = every.
Safe to use in infants < 6 wk
of age; used with ampicillin
in infants aged 2-8 wk
Dosage and Route
Ampicillin 100 mg/kg/day IV/IM divided q8h
Gentamici Term neonates < 7 days: 3.5-5
mg/kg/dose IV q24h
Used with gentamicin in
neonates < 2 wk of age;
for enterococci and
patients allergic to
Monitor blood levels
and kidney function if
therapy extends >48 h
Infants and children < 5 years: 2.5
mg/kg/dose IV q8h or single daily
dosing with normal renal function of
5-7.5 mg/kg/dose IV q24h
Children ≥5 y: 2-2.5 mg/kg/dose IV
q8h or single daily dosing with normal
renal function of 5-7.5 mg/kg/dose IV
Note: IM = intramuscular; IV = intravenous; q = every.
Antibiotic Agents for the Oral Treatment of Urinary
Tract Infection
Sulfamethoxazole and
trimethoprim (SMZ-TMP)
Amoxicillin and clavulanic acid
Daily Dosage
30-60 mg/kg SMZ, 6-12 mg/kg TMP
divided q12h
20-40 mg/kg divided q8h
50-100 mg/kg divided q6h
8 mg/kg q24h
10 mg/kg divided q12h
5-7 mg/kg divided q6h
*Nitrofurantoin may be used to treat cystitis. It is not suitable for the treatment
of pyelonephritis, because of its limited tissue penetration.
Complication of pyelonephritis :
focal inflammation of the kidney (focal pyelonephritis)
or renal abscess.
scar formation. Approximately 10-30% of children with
UTI develop some renal scarring; however, the degree
of scarring required for the development of long-term
sequelae is unknown.
Long-term complications of pyelonephritis are
hypertension, impaired renal function, and end-stage
renal disease.
• Definition
Is the retrograde passage of urine from the bladder into the
upper urinary tract.
• prevalence
VUR is present in approximately 1 percent of newborns .
The prevalence is high in children with febrile and non-febrile
urinary tract infections (UTIs), ranging from 30 to 45 percent .
There is significant ureteral dilation
and tortuosity
Left sided grade V reflux
Massive reflux grossly dilates the
collecting system. All the calyces are
blunted with a loss of papillary
VUR is divided into two categories :
• Primary VUR : the most common form of reflux, is due
to incompetent or inadequate closure of the
ureterovesical junction (UVJ), which contains a segment
of the ureter within the bladder wall (intravesical
In primary VUR, failure of this anti-reflux mechanism is
due to the shortening of the intravesical ureter
• Secondary VUR : is a result of abnormally high pressure in the bladder
that results in failure of the closure of the UVJ during bladder
Secondary VUR is often associated with anatomic (eg, posterior urethral
valves) or functional bladder obstruction (eg, dysfunctional voiding and
neurogenic bladder)
• The diagnosis of vesicoureteral reflux (VUR) is based upon the
demonstration of reflux of urine from the bladder to the upper
urinary tract by either contrast voiding cystourethrogram (VCUG)
or radionuclide cystogram (RNC). Although there is increased
radiation exposure with VCUG compared with RNC, VCUG
provides greater anatomic detail.
• Grade I – Reflux only fills the ureter without dilation.
Left sided grade I reflux
Grade II – Reflux fills the ureter and the collecting system without
Grade III – Reflux fills and mildly dilates the ureter and the collecting
system with mild blunting of the calyces
Grade IV – Reflux fills and grossly dilates the ureter and the collecting
system with blunting of the calyces. Some tortuosity of the ureter is also
Grade V – Massive reflux grossly dilates the collecting system. All the calyces
are blunted with a loss of papillary impression, and intrarenal reflux may be
present. There is significant ureteral dilation and tortuosity.
• Prenatal presentation The presence of vesicoureteral reflux
(VUR) is suggested by the finding of hydronephrosis on prenatal
In fetuses with prenatally diagnosed hydronephrosis, the reported
prevalence of VUR ranges from 10 to 40 percent
prenatal hydronephrosis was defined as a renal pelvic diameter
(RPD) ≥4 mm during the second trimester and ≥7 mm during the
third trimester
Postnatal presentation
Postnatal diagnosis of VUR usually is made after an episode of UTI,
and less commonly after family screening of an index case.
Children with a febrile UTI have a higher risk for abnormalities of
the genitourinary tract, including VUR and obstructive uropathy
Management of VUR
medical therapy
The following are single daily doses of commonly used
antimicrobial agents:
Trimethoprim-sulfamethoxazole (TMP-SMX) or TMP
alone − Dosing is based on TMP at 2 mg/kg
Nitrofurantoin − 1 to 2 mg/kg
Cephalexin − 10 mg/kg
Ampicillin − 20 mg/kg
Amoxicillin − 10 mg/kg
medical therapy
• Antibiotic prophylaxis is usually continued until there is
spontaneous resolution of VUR or surgical correction.
• Grades III to V at risk for recurrent pyelonephritis and possible
renal scarring, and potentially chronic kidney disease (CKD
• All patients with grades III to V VUR regardless of age receive
antibiotic prophylaxis
• Surgical correction is considered and discussed with the family
for children with the following conditions:
• Grade IV/V reflux in children older than two or three years of
age with persistent high-grade reflux or who have
breakthrough infection
• Children who fail medical therapy and have breakthrough
infections, who have significant side effects from continuous
prophylactic antibiotic coverage, or whose families are not
compliant with a long-term medical regimen.
• Grade I and II Children with grade I or II reflux are at a lower
risk for pyelonephritis and renal scarring, and are more likely
to have spontaneous resolution of their VUR.