Urinary Tract Infection in Children

IN CHILDREN
URINARY TRACT
INFECTION
DR. A. STEWART
MEDICAL INTERN

A Urinary Tract Infection is an infection in any part of your
urinary system.
INTRODUCTION

• It is the colonization and multiplication of micro organisms
(mainly bacteria) in the urinary system.
• It is further defined as the presence of a pure growth of more
than 105 colony forming units (CFU) of bacteria per ml of
urine.
• Lower counts of bacteria may be clinically important,
especially in boys and in specimen obtained by urinary
catheter or supra pubic aspiration.
• UTI is best defined as significant bacteriuria of a clinically
relevant uropathogen in a symptomatic patient. Most patients
with UTI also have pyuria, although there are exceptions.

INCIDENCE
• Boys are more susceptible to UTIs than girls before 6 months
of age, thereafter the incidence is substantially higher in girls
than boys.
1st year: M > F 5 : 1
Beyond 1st year: M < F 10 : 1
EPIDEMIOLOGY

• The prevalence of UTI is approximately 7% in febrile infants
and young children but varies by age, sex and circumcision
status.
• The prevalence is highest among uncircumcised boys particularly
those who are younger than three months.
• Females have a two to four fold higher prevalence of UTI than
do circumcised males.
• Awareness of prevalence of UTI in various subgroups of children
enables the clinician to grossly estimate the probability of infection in
the patient.
PREVALENCE

1. Pyelonephritis ( Upper Urinary Tract Infection)
2. Cystitis (Lower Urinary Tract Infection)
3. Asymptomatic Bacteriuria
CLASSIFICATION

Recurrent Urinary Tract Infections
Relapsing Urinary Tract Infections
Persistent Urinary Tract Infections
Complicated Urinary Tract Infection
Uncomplicated Urinary Tract Infection
OTHER CLASSIFICATIONS

Pyelonephritis: inflammation of renal pelvis and parenchyma.
Cystitis: inflammation of the bladder and the urethra.
Asymptomatic bacteriuria: positive urine culture without any
manifestations of infection.
TERMINOLOGIES

Recurrent Urinary Infections: Greater than 3 symptomatic UTI
within 12 months following clinical therapy.
Relapsing Urinary Tract Infections: Recurrent UTI caused by a
different pathogen at any time. Also known as Re-infection.
Persistent Urinary Tract Infections: UTI that maintains during
and after treatment.
TERMINOLOGIES

Complicated UTI
Urinary Tract Infection that has metabolic, functional and
anatomical alterations. May involve both lower and upper tract and
they significantly increase the risk of therapy failures.
Uncomplicated UTI
Urinary Tract Infection that affects mainly the lower urinary tract
and is without anatomic alterations.
TERMINOLOGIES

1. Escherichia coli -------- 80 %
2. Klebsiella spp ------------20%
3. Proteus mirabilis ---------- %
Enterobacter spp
Pseudomona aeruginosa
Staphylococcus saprophyticus
Adenoviruses
Enteroviruses
Coxackieviruses
Echoviruses
Adolescents:
Chlamydia trachomatis
Estafilococcus Negative Coagulase
ETIOLOGY
• The normal urinary tract is sterile.
• Normal Periurethral bacterial flora:
Healthy girls: Lactobacilli
Infants and Toddlers: E. coli and
Enterococcus
• Contamination by bowel flora may
result in urinary infection if a virulent
organism is involved or if the child is
immunosuppressed.

PATHOGENESIS
Routes of Infection:
** Ascending (Most common route)
* Hematogenous
- Lymphatogenous
- Contiguous (Direct extension from organs)
In the Neonatal period: hematogenous spread is frequent.
In other age groups: ascension to the ureter and kidneys.

PATHOGENESIS
The periurethral area is
colonized by
uropathogenic enteric
pathogens that ascends
throughout the urethra
upwards toward the
bladder.

PATHOGENESIS
* Fimbria allow bladder epithelial
cell attachment and penetration.
* Following penetration, bacteria
continue to replicate and may
form biofilms.

PATHOGENESIS
1. Once sufficient
bacteria colonization
occurs, bacteria may
ascend on the ureter
towards the kidney.
2. Fimbria aid in the
ascension process.
.

PATHOGENESIS
1. Infection of the
renal
parenchyma
causes an
inflammatory
response called
pyelonephritis.
2. Infection of the
renal
parenchyma can
also be caused by
hematogenous
spread.

PATHOGENESIS
1. If the
inflammatory
cascade continues,
tubular obstruction
and damage occur,
leading to
interstitial edema.
2. This may lead to
interstitial
nephritis causing
acute kidney
injury.

HOST FACTORS
Non Modifiable
Age
Female Gender
Previous UTIs
Family History
RISK FACTORS

• Uncircumcised Males
• Labial Adhesion
• Urethral Catheterization
• Dysfunctional voiding
• Constipation
• Bad hygiene
• Improper hygienic
practices
RISK FACTORS
• Urinary tract abnormalities:
- Vesicoureteral reflux
- Neurogenic bladder
- Obstructive uropathy
- Posterior urethral valves
HOST FACTORS
Modifiable

Age: The prevalence is higher in Males less than 1 year and
Females less than 4 years.
`
Lack of Circumcision: Uncircumcised male infants with
fever have a 4 to 8 fold higher prevalence of UTI than
circumcised male infant.
RISK FACTORS

Vesicoureteral reflux: VUR is the retrograde passage of urine
from the bladder into the upper urinary tract.
It is the most common urologic anomaly in children.
Female Infants: have a two – four fold higher prevalence of UTI
than male infants.
Presumed to be the result of the shorter female urethra and
propensity of bacterial attachment to the female periurethral
mucosa.
RISK FACTORS

Genetic Factors: First degree relatives of children with UTI are
more likely to have UTI than individuals without such history.
Adherence of bacteria may in part be genetically determined.
Uroepithelial cells of females who are non secretors of
blood group antigens have enhanced adherence of
uropathogenic Escherichia coli.

Urinary Obstruction: children with obstructive urologic
abnormalities are at risk of developing UTI. Stagnant urine is an
excellent medium for most uropathogens.
Anatomic conditions:
Posterior Urethral valves
Ureteropelvic junction obstruction
Myelomeningocele
Bladder/ Bowel dysfunction

Bladder and Bowel Dysfunctions:
a. Abnormal elimination pattern.
(Daytime wetting, frequent and infrequent voids,
urgency, infrequent stools.)
a. Bladder/ bowel incontinence.
b. Withholding maneuvers.
Bladder Catheterization: with increase duration of
bladder catheterization, the risk of UTI increase.

BACTERIAL FACTOR
• Bacteria with P Fimbriae
RISK FACTORS

• Urease: a high molecular weight cytoplasmic enzyme that
hydrolyzes urea to ammonia and carbon dioxide.
• Hemolysin: damages uroepithelium.
• Biofilm: formation of glycocalyx polymers on uroepithelial
surfaces, indwelling catheters and diaper fibers.
RISK FACTORS

CLINICAL FEATURES
• Clinical Features most often in UTIs depend on the age group and the
type of UTI.

CLINICAL FEATURES
Poor feeding
Lethargy
Failure to thrive
Jaundice
Offensive Urine

Children with UTI symptoms should be evaluated promptly.
Prompt recognition and treatment of UTI may be important in the prevention of
renal scarring.
History
• Fever (characteristics)
• Urinary symptoms (dysuria, frequency, urgency, incontinence)
• Abdominal pain, suprapubic discomfort and back pain.
• Recent illnesses
• Antibiotics administered,
• …and, if applicable, sexual activity.
CLINICAL EVALUATION

Risk factors for UTI
• Chronic urinary symptoms – Incontinence, lack of proper
stream, frequency, urgency, withholding maneuvers (suggestive of
bladder dysfunction)
• Chronic constipation
• Previous UTI or previous undiagnosed febrile illnesses in which
urine culture was not obtained.
PAST MEDICAL HISTORY

• Vesicoureteral reflux (VUR)
• Family history of frequent UTI, VUR, and other
genitourinary abnormalities
• Antenatally diagnosed renal abnormality
• Sexually activity: particularly if barrier contraception with
spermicidal agents is used (such methods predispose to UTI by
altering the normal vaginal flora

• Documentation of blood pressure and temperature
- Temperature ≥39°C (102.2°F) is associated with acute pyelonephritis
that may cause renal scarring.
- Elevated blood pressure may be an indication of renal scarring.
• Growth parameters
- Poor weight gain may be an indication of chronic renal failure due to
renal scarring
• Abdominal and flank examination
- Suprapubic and costovertebral angle tenderness is associated with UTI
- Enlarged bladder or kidney may indicate urinary obstruction and
palpable stool in the colon may indicate constipation, both of which predispose
to UTI
PHYSICAL EXAMINATION

• Examination of the external genitalia for anatomic abnormalities.
Example: phimosis, hypospadias, or labial adhesions and signs of vulvovaginitis,
vaginal foreign body, etc.
• Evaluation of the lower back for signs of occult myelomeningocele.
Example: midline pigmentation, lipoma, vascular lesion, sinus, tuft of hair), which
may be associated with a neurogenic bladder and recurrent UTI.
• Evaluation for other sources of fever; another source of fever decreases the risk
of UTI but does not eliminate it altogether
PHYSICAL EXAMINATION

The Differential Diagnosis depends on signs and symptoms and the results of the
urinalysis.
Fever without a source:
Pneumonia
Bacteremia
Fever, abdominal pain and pyuria:
Group A streptococcal infection
Appendicitis
Kawasaki disease
Asymptomatic bacteriuria:
Viral Gastroenteritis
DIFFERENTIAL DIAGNOSIS

Urine Culture:
First morning urine sample
Clean catch mid stream specimen
Collection bag
Supra pubic aspiration
Bladder catheterization
Urinalysis
Microscopic Examination
Urine Dipstick:
Leukocyte esterase
Nitrites
INVESTIGATIONS
CBC
Blood Culture
U & E
Imaging Techniques:
Renal Ultrasound
Renal Scintigraphy
CT Scan
MRI
VCUG

Algorithm for imaging decisions in children with urinary
tract infection.

Algorithm for urine testing in children with suspected
urinary tract infection (UTI).

Significant Bacteriuria depends on the method of sample collection used.
DIAGNOSIS

Acute management of UTI in children consists of antimicrobial therapy
to treat the acute infection and evaluation for possible predisposing
factors (E.g.: urologic abnormalities).
Objective of treatment of UTIs:
• Elimination of infection and prevention of urosepsis
• Relief of acute symptoms. E.g.: fever, dysuria, frequency
• Prevention of recurrence and long-term complications including
hypertension, renal scarring, and impaired renal growth and function.
MANAGEMENT

In Patient / Out Patient Treatment
Usual indications for hospitalization and/or parenteral therapy
include:
- Age <2 months
- Clinical urosepsis (e.g. toxic appearance, hypotension, poor
capillary refill)
- Immunocompromised patient

- Vomiting or inability to tolerate oral medication
- Lack of adequate outpatient follow-up
- Failure to respond to outpatient therapy

Empiric Therapy
Early antibiotic therapy (e.g. within 72 hours of presentation) may prevent renal
damage.
In one study, a delay in the treatment of febrile UTIs was associated with
increased risk for renal scarring; a delay of 48 hours or more increased the odds
of new renal scarring by approximately 47 percent.
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 factors and results of the urinalysis.
ANTIBIOTIC THERAPY

All properly diagnosed UTI should be treated even if asymptomatic and afebrile.
Following the antimicrobial spectrum and susceptibility:
If child is not vomiting:
Oral antibiotics
Cefuroxime: 30 mg/kg per day by mouth in two divided doses
-Cefixime: 8 mg/kg once daily
-Cefdinir: 14 mg/kg by mouth once daily
-Ceftibuten: 9 mg/kg by mouth once daily
MANAGEMENT

Parenteral Antibiotics
Ampicillin (100 mg/kg/day IV divided in four doses)
Gentamicin (7.5 mg/kg/day IV divided in three doses)
Cefotaxime (150 mg/kg per day IV divided in three or four doses)
Ceftriaxone (50 to 75 mg/kg per day IV)
Ceferino (100 mg/kg per day divided in two doses; maximum daily dose 4g)
Parenteral antibiotics should be continued until the patient is clinically
improved (E.g. afebrile) and able to tolerate oral liquids and
medications

BLOOD CULTURE
GRAM NEGATIVE: 14 days
GRAM POSITIVE: 10 days
NO GROWTH: 7 days
PRINCIPLES OF
ANTIBIOTIC TREATMENT

URINE CULTURE
GRAM NEGATIVE: 10 days
GRAM POSITIVE: 7 days
NO GROWTH: STOP/ 7days
PRINCIPLES OF
ANTIBIOTIC TREATMENT

It is generally not advised to provide prophylactic antibiotics to
children following a first febrile UTI, especially who do not have
VUR.
Medical therapy for VUR consists of daily prophylactic administration
of an antibiotic agent.
It is based on the assumptions that use of continuous antibiotics
results in sterile urine and the continued reflux of sterile urine does not
cause renal damage, as well as the observation that reflux
spontaneously resolves in most cases.
PROPHYLAXIS

Indications
• Patients with a history of UTI
• All patients who are not toilet-trained with VUR regardless of the
severity of grade, unless the family/caregiver prefers surveillance
and is compliant with medical advice and care.
PROPHYLAXIS

• All patients with bladder and bowel dysfunction (BBD) regardless
of the severity of VUR
• All patients with high-grade reflux (grade III to IV)
However, surveillance is an option for parents/caregivers who prefer
not to use prophylactic antibiotic therapy and are compliant with
medical advice and follow-up.
PROPHYLAXIS

The following are single daily prophylactic doses of commonly used
antimicrobial agents: (Administered at bedtime.)
●TMP-SMX or TMP alone – Dosing is based on TMP at 2 mg/kg
●Nitrofurantoin: 1 - 2 mg/kg
●Cephalexin: 10 mg/kg
●Ampicillin: 20 mg/kg
●Amoxicillin: 10 mg/kg
Antibiotic agents may be changed because of significant side effects or
resistance of organisms to the initial antibiotic choice.
PROPHYLAXIS

When treated properly and promptly, lower urinary tract infections rarely
lead to complications.
Left untreated, complications may include:
Recurrent Infections
Acute & Chronic pyelonephritis
Renal scarring
Hypertension
Chronic Kidney Disease
Hydronephrosis
COMPLICATIONS

Treatment of constipation
Circumcision in males.
Adolescent girls are advised to
urinate soon after intercourse.
Proper genital hygiene
Breast fed infants have less UTIs
than formula fed.
PREVENTION

• American Academy of Family Physicians, 2020, Urinary Tract Infections:
https://www.aafp.org/home.html
• Urinary Tract Infections in children older than 1 month, 2021:
Uptodate.com
• Metabolic adaptations of uropathogenic E. coli in the Urinary Tract, 2020:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5463501/
• https://doctorsaustralia.com.au/vc/topic/general-report/urinary-tract-
infections-in-children
BIBLIOGRAPHY

Urinary Tract Infection in Children

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