ASOGWA INNOCENT KINGSLEY
Infection of the urinary tract is identified
by growth of a significant number of
organisms of a single species in the
urine, in the presence of symptoms.
Recurrent UTI, defined as the recurrence
of symptoms with significant bacteriuria
in patients who have recovered clinically
following treatment, is common in girls.
UTI is a common bacterial infection in infants and
The risk of having a UTI before the age of 14 yrs
-1- 3% in boys
- 3-10% in girls .
In girls, the first UTI usually occurs by the age of 5
yr, with peaks during infancy and toilet training.
In boys, most UTIs occur during the 1st yr of life; more
common in uncircumcised boys.
During the 1st yr of life,
-M : F ratio is 2.8–5.4 : 1.
Beyond 1–2 yr,
-M : F ratio of 1 : 10.
◦ Cell Wall Antigens
◦ Serum Resistance
◦ Hemolytic Capability
◦ Growth Dynamics
◦ Iron Scavenging
◦ P Fimbriae
◦ Type 1 Fimbriae
◦ DR Fimbriae
HOST DEFENSE FACTORS
Urine pH / Vaginal pH
Local IgA Antibodies
Ascending Route of UTI
° Bacterial Colonization
° Migration to Periurethral Region
° Migration into Bladder
° Growth in Urine
° Bacterial Ascent to Kidney
° Colonization of Renal Medulla
° Focal Abscess Formation
° Kidney Re-infection
PATHOGENESIS - UTI
The 3 basic forms of UTI
Clinical pyelonephritis is characterized by any or all
of the following:
- abdominal or flank pain,
- malaise, nausea, vomiting, and,
- occasionally, diarrhoea.
In newborns show nonspecific symptoms :
- poor feeding, irritability, and weight loss.
Pyelonephritis is the most common serious
bacterial infection in infants <2 yrs of age who have
fever without a focus .
OUTCOMES OF PYELONEPHRITIS
Acute lobar nephronia (acute lobar nephritis) is a
localized renal bacterial infection involving >1 lobe
that represents either a complication of
pyelonephritis or an early stage in the development
of a renal abscess.
Renal abscess may occur following a
pyelonephritis or may be secondary to a primary
bacteremia (S. aureus).
Perinephric abscesses may be secondary to
contiguous infection in the perirenal area
(e.g., vertebral osteomyelitis, psoas abscess) or
pyelonephritis that dissects to the renal capsule.
Xanthogranulomatous pyelonephritis is a rare
type of renal infection characterized by
granulomatous inflammation with giant cells and
It may present clinically as a renal mass or an acute
or chronic infection.
Renal calculi, obstruction, and infection with
Proteus spp. or E. coli contribute to the
development of this lesion, which usually requires
total or partial nephrectomy.
It indicates that there is bladder involvement.
Symptoms include :
• suprapubic pain,
• incontinence, and
• malodorous urine.
Cystitis does not cause fever and does not result in
It refers to a condition that results in a
positive urine culture without any
manifestations of infection.
It is most common in girls.
The incidence is 1–2% in preschool
and school-age girls and 0.03% in
boys. The incidence declines with
Rapid evaluation and treatment of UTI is important
to prevent renal parenchymal damage and renal
scarring that can cause hypertension and
progressive renal damage.
◦ Culture Methods
◦ Screening Tests
◦ Anatomic / Functional Evaluation
◦ Age of Patient
◦ Severity of Infection
◦ Prior History of UTI
MANAGEMENT - UTI
UTI - VOIDING STUDY
VCUG For 1st Study
The patient’s age, features suggesting
toxicity and dehydration, ability to
retain oral intake and the likelihood of
compliance with medication(s) help in
deciding the need for hospitalization.
Therapy should be prompt to reduce
the morbidity of infection, minimize
renal damage and subsequent
Children less than 3 months of age and those with
complicated UTI should be hospitalized and treated
with parenteral antibiotics.
The choice of antibiotic should be guided by local
A third generation cephalosporin is preferred.
Therapy with a single daily dose of an
aminoglycoside may be used in children with
normal renal function.
Intravenous therapy is given for the first 2-3 days
followed by oral antibiotics once the clinical
Children with simple UTI and
those above 3 months of age
are treated with oral
With adequate therapy, there
is resolution of fever and
reduction of symptoms by 48-
The duration of therapy
-14 days for infants and children with complicated
- 7-10 days for uncomplicated UTI.
Adolescents with cystitis may be treated with
shorter duration of antibiotics, lasting 3 days.
Following the treatment of the UTI, prophylactic
antibiotic therapy is initiated in children below 1
year of age, until appropriate imaging of the urinary
tract is completed.
EVALUATION AFTER THE FIRST UTI
The aim of investigations is to identify patients at high
risk of renal damage, chiefly those below one year of
age, and those with VUR or urinary tract obstruction.
Evaluation includes ultrasonography, DMSA renal scan
and micturating cystourethrography (MCU) performed .
An ultrasonogram provides information on kidney size,
number and location, presence of hydronephrosis,
urinary bladder anomalies and post-void residual urine.
DMSA scintigraphy is a sensitive technique for detecting
renal parenchymal infection and cortical scarring.
MCU detects VUR and provides anatomical details
regarding the bladder and the urethra.
EVALUATION AFTER THE FIRST UTI
Ultrasonography should be
done soon after the diagnosis
The MCU is recommended 2-3
The DMSA scan is carried out
2-3 months after treatment.
PREVENTION OF RECURRENT UTI
Adequate fluid intake and frequent voiding
constipation should be avoided
In children with VUR who are toilet trained, regular
and volitional low pressure voiding with complete
bladder emptying is encouraged.
Double voiding ensures emptying of the bladder of
post void residual urine.
Circumcision reduces the risk of recurrent UTI in
infant boys, and might therefore have benefits in
patients with high grade reflux.
Long-term, low dose, antibacterial prophylaxis is
used to prevent recurrent, febrile UTI.
The antibiotic used should be effective, non-toxic
with few side effects and should not alter the growth
of commensals or induce bacterial resistance .
Antibiotic prophylaxis is recommended for
(i) UTI below 1-yr of age, while awaiting
(iii)frequent febrile UTI (3 or more episodes in
a year) even if the urinary tract is normal.
•VUR is a bladder valve defect
that allows urine to reflux from
the bladder through one or both
ureters and up to the
•Febrile urinary tract infection
(UTI) is the defining
VUR is seen in 40-50% infants and 30-50%
children with UTI, and resolves with age.
Its severity is graded using the International Study
Classification from grade I to V, based on the
appearance of the urinary tract on MCU.
The presence of moderate to severe
VUR, particularly if bilateral, is an important risk
factor for pyelonephritis and renal scarring, with
subsequent risk of hypertension, albuminuria and
progressive kidney disease.
The risk of scarring is highest in the first year of life
SCREENING OF SIBLINGS AND OFFSPRING:
Reflux is inherited in an autosomal dominant
manner with incomplete penetrance; 27% siblings
and 35% offspring of patients show VUR.
Ultrasonography is recommended to screen for the
presence of reflux.
Further imaging is required if ultrasonography is