Pediatric UTI and renal infection: etiology, disease presentation, management and follow- up.

1. Kidney and Urinary Tract Infections in Children
Nephrology Block
Fatima Farid - Pediatric Resident Year II

2. Contents
• Case presentation
• Definition
• Risk factors/ pathogenesis
• Clinical features
• Diagnosis
• Management
2

3. History
• A.A is a seven-year-old boy, previously healthy.
• Presented on 12/04/2019 with two weeks’ history of persistent fever.
• Child had daily fever up to 39 C responding to Adol every 4- 6 hours.
• Fever associated with sweating, but no shivering or abnormal movements.
• For the last 3 days before presentation, fever worsened to 40.3 C still responding to alternating Adol
and Voltaren every 4- 6 hours.
• Systemic review positive for fatigue, reduced appetite & definite weight loss of 2 kg since onset of
illness (25 to 23 kg).
• Child attends school and may have had an infectious exposure.
3

4. History
• No history of skin rash, runny nose, throat/ ear pain, cough, abdominal pain or change
in bladder/ bowel habits.
• No preceding animal exposure or fresh milk ingestion.
• Returned from Sudan six months prior and child was very well thereafter. No known
sick contact during travel.
• At onset of illness, child was taken to a private clinic where he was started on oral
Augmentin (in view of fever and congested throat – no investigations performed).
• Five days’ course of regular Augmentin completed with no improvement in condition.
4

5. History
• Taken back to same clinic, where doctor suspected Augmentin- resistant infection and prescribed
Cefixime.
• Four days’ course of Cefixime completed- last dose on 09/04/2019.
• As per mother, fever remained persistent with no improvement despite antibiotic therapy. There was
no day without fever since onset of illness.
• First attended LH ED on 09/04/2019. Child was febrile with raised inflammatory markers and sterile
pyuria. WBC 13.2, ANC 9.6, PLT 660, Hb 9.4, CRP 122, PCT 0.21, urine WBC 5- 10.
• Advised admission for observation and further investigations but signed DAMA.
• Returned on 12/04/2019 with high grade fever and lethargy then agreed for admission.
5

6. History
• Unremarkable past medical and surgical history.
• Born at term by NVD in Sudan. Birth weight 3.6 kg. Unremarkable antenatal and post- natal periods.
• Fully immunized.
• No regular home medications.
• No drug or food allergies. Consumes regular family diet.
• Attending Grade 2 with good school performance.
• No known family history of significance. No similar ill contact at home.
• No smokers or pets at home.
6

7. Vital Signs
Blood Pressure 101/ 79 mmHg
Pulse 138 beats/ min
Respiratory Rate 33 breaths/ min
SpO2 100%
Temperature 38.4 C
7

8. Physical Examination
• Constitutional:
Awake, alert, not in distress. Febrile. Mildly dehydrated. Well- perfused. Capillary refill
time less than two seconds. No skin rash noted. Pink on room air.
• HENT:
No nasal discharge noted. Throat clear with no tonsillar enlargement/ follicles. Right
ear canal waxy. Left tympanic membrane normal.
• Neck:
Few scattered small palpable submandibular, anterior and posterior cervical lymph
nodes. Small right axillary lymph node palpable.
8

9. Physical Examination
• Cardiovascular:
Normal heart sounds, no murmur audible. Femoral pulses palpable bilaterally.
• Pulmonary/Chest:
Bilateral equal air entry, no added sounds.
• Abdominal:
Soft, non- tender, non- distended. No palpable masses or organomegaly. Bowel sounds
audible.
• Genitourinary:
Normal male genitalia, circumcised. Bilateral palpable inguinal lymph nodes.
9

10. Initial Lab Reports
Hemoglobin 9.2
MCV, MCH 79, 26
Platelet Count 541
WBC 7.6
ANC, Neutrophil % 5.7, 75%
CRP 104.5
ESR 101
Urea/ Electrolytes Normal
Liver Function Tests Albumin 2.7, Globulin 4.5
Malaria PREP Malaria parasite not seen
10

11. Chest X- Ray
Report: Prominent vascular
markings. Parahylar haziness.
Normal heart shadow. Clear
costophrenic sinuses.
Conclusion: Parahylar
peribronchial consolidation
11

12. Management
• Child was empirically started on IV Ceftriaxone along with IV fluids and
fever management.
• Fever persisted continuously throughout admission.
• Further investigations were planned.
12

13. Further Investigations
Procalcitonin 0.1
Uric acid 1.8
Ferritin 126
LDH 167
Creatinine, CPK 0.3, 45
CMV/ EBV/ Mycoplasma pneumoniae Immune
Blood film Mild normochromic anemia
Direct Coomb’s Test Negative
Urine routine/ culture Normal/ No growth
Blood culture No growth
13

14. Progress
• Child was persistently febrile despite IV Ceftriaxone therapy.
• Investigations failed to reveal a specific underlying etiology till that point.
• It was decided to perform an abdominal ultrasound to detect a hidden
focus of infection.
14

15. Abdomen Ultrasound
• Left kidney within normal site and size
measuring 9.5*4.8 cm, cortex 1.8 cm. At the
middle pole of the kidney, there is evidence of
ill-defined, almost rounded shape,
heterogeneous echotexture, low vascular
mass lesion is seen and measuring 4*3 cm.
• No calcification seen inside the lesion and
no back pressure changes of the kidney.
15

16. CT abdomen with
contrast
• Left kidney is enlarged with a large
heterogeneous predominantly solid lesion
with multiple cystic areas seen in the middle
part of the left kidney measuring about 4.8 X
3.5 X 4.6 cm (CC, AP, TS) with multiple thick
septi and giving rise to cart-wheel
appearance.
• Multiple enlarged lymph nodes are noted in
the left renal hilum and paraaortic regions
measuring up to 1.8 cm.
16

17. Management
• Left- sided renal abscess diagnosed, and antibiotics upgraded to Amikacin and
Meropenem.
• Child was shifted to Pediatric Surgery Ward for further management.
• As per surgeons, abscess did not display significant liquefaction, hence no drainage was
performed.
• Fever resolved with conservative antibiotic therapy, and repeat abdomen ultrasound
showed signs of improvement.
• A total of 14 days antibiotic therapy was recommended, but parents wished to be
discharged against medical advice for personal reasons.
17

18. Definition
• There are 5 basic forms of urinary tract infections:
• Cystitis
• Pyelonephritis
• Asymptomatic bacteriuria
• Focal pyelonephritis (nephronia)
• Renal abscesses
18

19. Epidemiology
• UTIs occur in 1% of boys, and 1- 3% of girls. Prevalence varies with age.
• During first year of life, male to female ratio is 2.8- 5.4: 1, whereas beyond first year 1: 10
(M:F).
• In girls, the first UTI usually occurs by age of 5 years with peaks during infancy and toilet
training.
• Nearly all UTIs are ascending infections: bacteria arise from fecal flora, colonize perineum
and enter the bladder via the urethra. In uncircumcised boys, bacterial pathogens arise
from the flora beneath the prepuce.
• Rarely, renal infection occurs by hematogenous spread (neonates or as in endocarditis).
19

20. Risk Factors
20
Female gender White race
Uncircumcised
male
Vesico- uretral
reflux
Toilet training
period
Voiding dysfunction
Wiping back to
front in girls
Bubble baths Tight underwear Pinworm infection Constipation
Bacteria with P
fimbrae
Neuropathic
bladder
Family history of
UTI
Urethral
instrumentation
Pregnancy, sexual
activity
Anatomic
abnormalities (labial
adhesions, posterior
urethral valves, pelvi-
ureteral junction
obstruction)

21. What is the pathogenesis of UTI here?
• Six-year-old girl with recent move to a new school, now comes with frequent painful enuresis in bus
ride home? (5 points)
• Twelve-year-old boy with global developmental delay & spastic quadriplegic CP noted to have fever
and foul- smelling urine? (4 points)
• Two-year-old uncircumcised boy with abnormal urinary tract comes with high grade fever and
lethargy? (3 points)
• Five-year-old boy with severe night- time perianal itching and now with burning urination? (1 point)
• One-year-old girl known to have labial adhesions since birth, presents with fever and excessive crying
during urination? (1 point)
21

22. What is the pathogenesis of UTI here?
• Six-year-old girl with recent move to a new school, now comes with frequent painful enuresis in bus ride home?
(female, voiding dysfunction, tight underwear, wiping back to front, constipation)
• Twelve-year-old boy with global developmental delay & spastic quadriplegic CP noted to have fever and foul-
smelling urine? (uncircumcised, neuropathic bladder, urethral instrumentation, constipation)
• Two-year-old uncircumcised boy with abnormal urinary tract diagnosed comes with high grade fever and lethargy?
(uncircumcised, VUR, PUV)
• Five-year-old boy with severe night- time perianal itching and now with burning urination? (pinworm infection)
• One-year-old girl known to have labial adhesions since birth, presents with fever and excessive crying during
urination? (labial adhesions)
22

23. Pathogenesis
• If there is grade III, IV, or V vesicoureteral reflux and a febrile UTI, 90% have evidence of acute
pyelonephritis on renal scintigraphy or other imaging studies.
• In girls, UTIs often occur at the onset of toilet training because of bladder/bowel dysfunction that
occurs at that age. The child is trying to retain urine to stay dry, yet the bladder may have uninhibited
contractions forcing urine out. The result may be high-pressure, turbulent urine flow or incomplete
bladder emptying, both of which increase the likelihood of bacteriuria.
• Bladder/bowel dysfunction can occur in the toilet-trained child who voids infrequently. Similar
problems can arise in school-age children who refuse to use the school bathroom.
• Obstructive uropathy resulting in hydronephrosis increases the risk of UTI because of urinary stasis.
23

24. Pathogenesis
• Urethral catheterization for urine output monitoring or during a voiding cystourethrogram or
nonsterile catheterization can infect the bladder with a pathogen.
• Constipation with fecal impaction can increase the risk of UTI because it can cause bladder
dysfunction.
• Anatomic abnormalities precluding normal micturition, such as a labial adhesion: this lesion
acts as a barrier and causes vaginal voiding.
• A neuropathic bladder can predispose to UTIs if there is incomplete bladder emptying
and/or detrusor– sphincter dyssynergia.
• The incidence of UTI in infants who are breastfed is lower than in those fed with formula.
24

25. Microbiology
• Escherichia coli is the most common bacterial cause of UTI; it accounts for approximately 80 percent of UTI in
children.
• Other gram-negative bacterial pathogens include Klebsiella, Proteus, Enterobacter, and Citrobacter.
• Gram-positive bacterial pathogens include Staphylococcus saprophyticus, Enterococcus, and, rarely,
Staphylococcus aureus.
• Viruses (eg, adenovirus – 11 and 21, enteroviruses, Coxsackieviruses, echoviruses) and fungi (eg, Candida spp,
Aspergillus spp, Cryptococcus neoformans, endemic mycoses) are uncommon causes of UTI in children.
• Viral UTI are usually limited to the lower urinary tract.
• Risk factors for fungal UTI include immunosuppression and long-term use of broad-spectrum antibiotic therapy,
and indwelling urinary catheter.
25

26. Clinical features in
newborns and infants
• Fever or hypothermia
• Poor feeding
• Irritability, lethargy
• Vomiting
• Abdominal pain
• Strong, foul- smelling urine
• Cloudy or blood tinged urine
• Jaundice
• Failure to thrive
26

27. Clinical features in children
Lower urinary tract infection
• Dysuria
• Frequency
• Urgency
• Supra- pubic pain
• Incontinence/ enuresis
• Malodorous urine (non- specific)
• Bloody urine
Upper urinary tract infection
• Fever
• Abdominal/ flank pain
• Malaise, lethargy, irritability
• Nausea, vomiting
• Diarrhea
• Poor feeding
• Weight loss
27

28. 28
Source: 100 Cases

29. 29
Source: 100 Cases

30. Clinical approach – History
• Height and duration of fever
• Urinary symptoms (dysuria, frequency, urgency, incontinence)
• Supra- pubic discomfort, back/ abdomen pain
• Vomiting
• Recent illness
• Antibiotic therapy administered
30

31. Clinical approach – History
• Chronic urinary symptoms: incontinence, lack of proper urine stream, frequency,
urgency, withholding maneuvers (suggesting bladder dysfunction)
• Chronic constipation
• Previous UTI or undiagnosed febrile illness in which urine culture was not obtained
• Vesico- ureteral reflux
• Family history of frequent UTI, VUR or other genitourinary abnormalities
• Antenatally diagnosed renal/ urinary tract anomaly
31

32. Clinical approach – Physical examination
• Documentation of blood pressure and temperature
• Growth parameters
• Abdominal and flank examination
• Examination of external genitalia
• Evaluation of lower back for signs of occult meningomyelocele
32

33. Clinical approach – Physical examination
• Temperature > 39C is associated with acute pyelonephritis which may lead to renal scarring
• Elevated blood pressure may indicate renal scarring
• Poor weight gain may be an indication of chronic renal failure due to renal scarring
• Supra- pubic and costo- vertebral angle tenderness must be elicited
• Enlarged bladder or kidney may indicate urinary obstruction
• Palpable stool in the colon may indicate constipation
• External genitalia should be checked for anatomic abnormalities (phimosis or labial adhesions), signs of
vulvovaginitis, vaginal foreign body or evidence of STDs
• Back may reveal midline pigmentation, lipoma, vascular lesions, sinus, tuft of hair which could thereby lead to
neurogenic bladder and recurrent UTI
33

34. Diagnosis
• UTI may be suspected based on symptoms, findings on urinalysis or both.
• Urine culture is necessary for confirmation and appropriate therapy.
• Methods of urine collection:
• Mid- stream urine sample
• Urinary catheterization
• Bag collection
• Supra-pubic aspiration
34

35. Urine dipstick interpretation
35
Nitrites are more specific for UTI but
can be falsely negative as bacteria
needs to sit in bladder for one hour to
allow enough nitrite production
Leukocyte esterase can be positive in
several other conditions: partially
treated bacterial UTI, viral UTI, renal
TB/ abscess, appendicitis, Kawasaki
dse, Crohn’s dse, interstital nephritis.
Source: DH UTI Guidelines

36. Urine routine interpretation
36

37. Urine culture interpretation
37

38. 38
Source: PREP 2016

39. 39
Source: PREP 2016

40. Management
• NICE guidelines regarding antibiotic treatment are
as follows:
• Age <3 months: IV antibiotics — precise duration not
stated, but sensible to administer for 2–3 days prior
to switch to oral antibiotics if clinically improved;
• Age > 3 months, but with upper tract UTI: oral
antibiotic with low resistance pattern for 7–10 days;
IV antibiotics for 2–4 days if vomiting, then oral
antibiotics for a total of 10 days;
• Age > 3 months with lower urinary tract symptoms:
oral antibiotics for 3 days.
• If a child is on prophylaxis, change the antibiotic
rather than increasing the dose.
40
Source: DH UTI Guidelines, Oxford Handbook of Pediatric Nephrology

41. Intravenous antibiotic therapy
• In-hospital parenteral therapy generally is indicated for children with:
• Age < 2 months
• Clinical urosepsis (eg, toxic appearance, hypotension, poor capillary refill)
• Immune compromise
• 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
41
Source: UpToDate- Urinary tract infections in infants older than one month and young children: Acute management, imaging, and prognosis

42. Intravenous antibiotic therapy
• Cephalosporins (eg, cefotaxime, ceftriaxone, cefepime) and aminoglycosides
(eg, gentamicin) are appropriate first-line parenteral agents for empiric
treatment of UTI in children. Definitive therapy is based upon the results of
urine culture and sensitivities.
• Acceptable inpatient treatment regimens include the combination
of ampicillin and gentamicin; gentamicin alone; or a third- or fourth-generation
cephalosporin. Ampicillin should be included if enterococcal UTI is suspected.
42
Source: UpToDate- Urinary tract infections in infants older than one month and young children: Acute management, imaging, and prognosis

43. 43
Source: UpToDate- Urinary tract infections in infants older than one month and young children: Acute management, imaging, and prognosis

44. Oral antibiotic therapy
• For children with low risk of renal involvement (fever ≤39°C [102.2°F], not toxic-appearing), we prefer
a first-generation cephalosporin (eg, cephalexin 50 to 100 mg/kg per day by mouth in two divided
doses) provided that the local resistance of E. coli to first-generation cephalosporins in the specific
community is not high (eg, ≥15 percent).
• For children with a high likelihood of renal involvement (ie, fever >39°C [102.2°F] with or without back
pain) or immune deficiency, we generally use a second-generation (eg, cefuroxime) or third-
generation cephalosporin (eg, cefixime, cefdinir, ceftibuten).
• The predicted probability of resistance to first-generation cephalosporins, trimethoprim-
sulfamethoxazole, or amoxicillin is relatively high, and the tissue concentrations of nitrofurantoin may
not be adequate to eradicate the causative organism.
44
Source: UpToDate- Urinary tract infections in infants older than one month and young children: Acute management, imaging, and prognosis

45. 45
Source: UpToDate- Urinary tract infections in infants older than one month and young children: Acute management, imaging, and prognosis

46. Imaging studies
• The initial US will identify serious structural
abnormalities and urinary obstruction;
bladder wall thickness and emptying; renal
defects.
• DMSA scan is considered the gold standard
investigation for the diagnosis of renal
parenchymal damage. It should be delayed
until 4–6 months after the acute UTI in order
to avoid a false positive result due to renal
parenchymal inflammation that may resolve.
• MCUG is considered the gold standard
investigation for the diagnosis of urethral
abnormalities and VUR.
46
Source: DH UTI Guidelines, Oxford Handbook of Pediatric Nephrology

47. 47
Source: DH UTI Guidelines

48. 48
Source: Oxford Handbook of Pediatric Nephrology

49. Long term management
• High fluid intake to produce a high urine output
• Regular voiding
• Complete bladder emptying using double micturition to empty any residual or
refluxed urine returning to the bladder
• Prevention or treatment of constipation
• Good perineal hygiene
• Lactobacillus acidophilus to encourage colonization of the gut by this organism
49

50. Antibiotic prophylaxis
• NICE guidelines do not recommend the routine use of prophylactic antibiotics in infants and children
following a first UTI, although this may be considered in those with recurrent UTI, defined as:
• two or more upper UTIs;
• one upper UTI plus one or more lower UTI;
• three or more lower UTIs.
• Commonly, prophylaxis is used in those under 2 years of age and those with ureters that are dilated
up to the renal pelvis. Trimethoprim (2mg/kg at night) is used most often, but nitrofurantoin (1mg/kg at
night) or nalidixic acid (7.5mg/kg bd) may be given.
• Broad spectrum, poorly absorbed antibiotics, such as amoxicillin should be avoided.
50
Source: Oxford Handbook of Pediatric Nephrology

51. Follow- up
• NICE guidelines state that children who do not undergo radiological investigation following UTI do not require follow-up
• Routine urine culture in well children is not necessary
• There is no evidence for when antibiotic prophylaxis (if used) should be stopped. This should be considered at the age of 2 years (by
when maximum renal growth has occurred) or after 1 year free of UTIs
• Any child with a renal defect requires annual BP checks for life. Hypertension has been reported in up to 10 % , but such a high
incidence has been questioned
• Regular assessment of renal function and growth using US, and early morning urine stick testing for proteinuria for those with
bilateral renal defects, who are at risk of progressive CKD
• No further imaging is necessary in a child with no or unilateral defects with no further infections
• Circumcision may benefit boys with recurrent UTIs. It has been estimated that around 100 circumcisions are required to prevent one
UTI.
• If there are further symptomatic UTIs, investigations are required to determine whether there are new scars or continuing VUR.
51
Source: Oxford Handbook of Pediatric Nephrology

52. References
• Oxford handbook of Pediatric Nephrology
• Nelson Textbook of Pediatrics - Volume 2, 20th Edition.
• Urinary tract infections in children: Epidemiology and risk factors (UpToDate)
• Urinary tract infections in infants and children older than one month: Clinical features and diagnosis (UpToDate)
• Urinary tract infections in infants older than one month and young children: Acute management, imaging, and prognosis (UpToDate)
• Urinary tract infections in children: Long-term management and prevention (UpToDate)
• Urine collection techniques in infants and children with suspected urinary tract infection (UpToDate)
• Urinary tract infections in neonates (UpToDate)
• Dubai Hospital UTI Guidelines
52

53. Thanks 
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