Paediatric Nephrology

1. Urinary tract infection
in children
PROF ENOBONG IKPEME

2. INTRODUCTION
UTI is a common bacterial infection in children that may
lead to substantial morbidity that is not limited to the
acute period of the illness.
PREVALENCE
In infancy,M:F= 3-5:1.
Beyond infancy, 1-2 years; the M:F =1:10
Approximately 3.5% of girls and 1% of boys acquire UTI by
age 11 years.
Average age in girls is 3 years coinciding with the period of
toilet training

3. In boys ,the first year of life is associated with
abnormalities of the renal tract- commonest being
vesicouretheral reflux (VUR). Other are posterior urethral
valve, ureterocoele, bladder diverticulum, neurogenic
disorder like spina bifida, calculi,hydronephrosis, pelvic
ureteric junction obstruction, bladder tumours. There is
also a 10-20 fold increase incidence in uncircumcirsed
males.
UTI is the commonest nosocomial infection in children
with prolonged hospital admission especially in those with
urinary tract diseases.

4. AETIOPATHOGENESIS
 Nearly all UTIs are ascending infections through
the urethra from the bowel flora in the perineum.
 In early infancy haemotogenous spread occurs
although this is rare in older children.
 Aetiological agents
1. Enterobacteriaceae ( E.coli 75-80% is by far the
leading cause in all age groups, Klebsiella,
Proteus, pseudomonas and citrobacter)

5. Aetiological agents
2. Gram positive cocci- enterococcus,
staphylococcus aureus, staphylococcus epididermis.
In females 75- 90% of UTIs are caused by E.coli then
Klebsiella and proteus.
Proteus reported in males > 1 year.
Gram +ve bacteria are more common in males
Staph aureus – pathogen in both sexes
3. Viruses (adenovirus) especially cystitis which may
be hemorrhagic.

6. Nosocomial significant bacteriuria
caused by Klebsiella 47.3%, Staph
aureus 31.6%, E.coli 10.5%,
Pseudomonas 5.3%, Citrobacter 5.3%.
Newborn : Klebsiella and E.coli

7. CLASSIFICATION
 Difficult to delineate in children
 Urethritis-limited to the urethra
 Cystitis- to the bladder,
 Pyelitis – to the renal pelvis
 Pyelonephritis- to the renal parenchyma
Severe forms of UTI occur with clinical features like
loin pain, tenderness,rigors along with other clinical
features of UTI. This may result in renal injury
termed pyelonephritic scarring.

8. CLINICAL MANIFESTATIONS
Varies with agr
1st episode may be asymptomatic
Fever is the most common symptom
Straining on micturition
Dribbling or poor urine stream that is
often voided intermittently characterizes
urethral obstruction

9. 3 BASIC CLINICAL TYPES
1. CYSTITIS: dysuria,urgency, frequency, suprapubic
pain,incontinence and malodorous urine. Usually
doesn’t cause fever or result in renal injury
2. CLINICAL PYELONEPHRITIS- abdominal or flank pain,
fever,malaise, nausea, vomiting, jaundice in neonates
and occasional diarrhea. Newborns may also present
with non specific symptoms like poor feeding,
irritability, weight loss or poor weight gain.
3. Asymptomatic bacteriuria- positive urine culture
without any manifestations of infection. Occurs mostly
in girls and does not cause any renal injury

10. Diagnosis of UTI
 1) Urine microscopy and culture in any child with the above symptoms.
 Urine collection
- Mid stream in older children
- Clean catch in infants
- Supra-pubic puncture
- Catheterisation
- Urine should be collected in a universal sterile container and sent to the
laboratory immediately for examination within 2 hours. In event of delay it
should be stored in the refrigerator at 4 degrees celcius

11.  it could also be transported in 1.8% boric acidto
preserve pus cells bacteria without inhibiting growth of
pathogen
 CULTURE: MacConkey and blood agar
 DIAGNOSIS is made
a) if in one specimen, there’s a pure growth of >10^5
bacteria per ml
b) Any growth on culture of suprapubic urine specimen
c) Growth of >10^4/ml in catheter urine specimen

12. PYURIA
 PYURIA : > 10 WBC/ml of uncentrifuged urine. Usual in UTI
 NITRITE TEST: positive in UTI . Due to bacterial conversion of nitrate to nitrite
by nitrate reductase in certain bacteria. Urine needs to stay in the bladder
for atleast 1 hour.
 Positive leucocyte esterase test
 Increased WBC
 Increased ESR
 Increased Creactive protein

13. Differential diagnosis
1. Malaria
2. Pneumonia
3. Severe pharyngitis
4. Acute otitis media

14. TREATMENT
 TRIMETHOPRIM (7mg/kg/day)- SULFAMETHOXAZOLE for 7-10 days
 NITROFURANTION 5-7mg/kg/day in 3-4 divided doses
 NEONATES: Parenteral antibiotics for 10-14 days
 PYELONEPHRITIS IN OLDER CHILDREN: Ceftriaxone and gentamicin
 Urine culture should be repeated a week after completing antibiotic
treatmrnt
 Periodically ,for 1-2 years repeat urine culture even when the child is
asymptomatic.
 Prophylaxis against re-infection is useful.1/3 of therapeutic dose is used(
nitrofurantoin 1-2mg/kg/night or cotrimoxazole 2 mg/kg/night)

15. Indications for prophylaxis in UTI
Neurogenic bladder
Urinary obstruction and stasis
Reflux and calculi
Chemoprophylaxis is usuallt for 6
months to 2-5 years depending on the
background illness.

16. COMPLICATIONS and Follow up
 Recurrent UTI from VUR
 Renal scarring -20%
 Hypertension 10%
 ESRFF 10%
 VUR:GradeI- V, III to V most likely associated
with renal scarring
 Reflux nephropathy is more common in girls
resulting in pyelonephritis

17. Recurrence rate of 30%- 40%. In girls it is
more substantial regardless of the
presence or absence of anatomical
abnormalities.
Recurrence is more of re-infection from
bowel flora rather than a relapse with the
same organism isolated at the initial
infection

18. SUBSEQUENT EVALUATION
 Necessary after 1st proven UTI
 Imaging studies
 Plain abdominal Xray to exclude- radiopaque
stones,lumbo-sacral spinal defects.
 Ultrasonography- defines more clearly distinguishing
renalagenesis,hydronephrosis,renal stones,cystic
kidneys,renal tumours, acute pyelonephritis- enlarged
kidneys,demonstrate renal scars in 30% of cases,
perirenal and renal abscesses./

19. Voiding cystourethrogram VCUG
 Usually done when urine is sterile. It is indicated in :
a. All children less than 5 years
b. All febrile UTIs
c. School aged girls who have had more than 2 UTIs
d. Any male with UTI
e. All neonates with UTI
40% show VUR

20. Excretory urography (intravenous
urogram IVU)
 It gives a more detailed view of the upper
tract
RADIONUCLIDE RENAL IMAGING.
This provides both anatomical and functional
information about the kidney. The commonly
used agents are technicium ,
diethylenetriamine pertracetic acid(DTPA),
Dimercaptosuccinic acid (DSMA),
glucoheptonate (GHA) and 123 I- hipuran

21. DSMA AND GHA
 Is useful in imaging renal parenchyma and can detect ectopic
kidneys,renal scars and other parenchymal lesions
 AGE
<1years: USS,DSMA after 3months and IVU if DMSA is
unavailable.
1-7 years- as above and VCUG should be done in those with
-proven renal tract abnormalities.
-hx suggestive of pyelonephritis
-recurrent infections
-FHx of reflux

22. > 7YEARS
VCUG rarely needed except in
abnormality of the upper renal tract or
previously detected with reflux

23. outcome
Most neonates : UTI heals completely.
In some especially those with VUR and
inadequate antibiotic, UTI may lead to:
-renal scarring
-hypertension
ESRF in later childhood

24. Prevention
1. Treatment of underlying voiding dysfunction.
2. Treatment of constipation
3. Proper toilet training and wiping from front
backward
4. Circumcision
5. Chemoprophylaxis in recurrent UTIs
6. Surgical correction of renal tract abnormalities