1. Urinary Tract Infections in Children
Dr. Rim El-Rifai
Consultant Paediatrician
QMHC

2. Outline of talk Cases Introduction and definitions Evaluation of UTI
Management
Summary

3. 7 year old girl Initial referral to investigate secondary enuresis,
had a “positive urine for UTI”
Main concern nocturnal enuresis
Dysuria and dark offensive urine
History of PUO’s for 2 days at a time
No abnormal physical findings on examination

4. investigations Ultrasound scan KUB: DMSA:
Small capacity bladder, dilated distal ureter and urothelial thickening in Lt renal pelvis and large left kidney on USS
DMSA:
left Duplex with scarring of upper pole- has patient had MCU?

5. 3 weeks old girl Initial presentation to A&E: vomiting
Treated with IV AB’s
2 urine samples had mixed growth but > 100 WBC on SPA
FH: brother had pyloric stenosis and UTI when 4 mo old
TMP ran out after 2 weeks- did not get prescription

6. Investigations KUB USS normal Abdo. USS: Pyloric Stenosis
MCUG and DMSA awaited

7. 6 years old girl
Referred by GP for frequency and day time wetting at school
Urine showed no WBC but grew Enterococcus
treated as UTI with oral TMP
History: frequency and urgency but not unwell or febrile
Further urine dipstick and KUB normal
On questioning: urine collected in make shift jar at home

9. What is a UTI?
An inflammatory response of urothelium to bacterial invasion that is usually associated with bacteriuria and pyuria
i.e. MSU shows:
WBC > 10
Pure growth of organisms > 107

10. Bacteriuria
Presence of bacteria in the urine in numbers exceeding the numbers caused by contamination from skin, urethra
Not a contaminant from the skin, vagina, prepuce
Collection technique sensitive
May be asymptomatic

11. Pyuria Presence of white blood cells (WBCs) in the urine
Generally indicative of an inflammation of the urothelium as a response to bacterial invasion

12. Sites of origin of UTI Acute pyelonephritis:
acute bacterial infection of the kidney
Fever, rigors
Flank pain
Bacteriuria and pyuria
Unwell child, usually febrile

13. Sites of origin of UTI Bacterial Cystitis: Inflammation of the bladder
Abrupt onset of dysuria
Frequency
Urgency
Suprapubic pain
Non-bacterial cystitis: chemical

14. Sites of origin of UTI Urethritis Inflammation of the urethra
Symptoms difficult to differentiate from cystitis
Seen in girls with vulvovaginitis

15. UTI in Childhood Features commonly non-specific
Associated with anatomical Urological abnormalities
Difficulty in obtaining meaningful urine samples
Tendency to cause renal scarring
May lead to End Stage Renal Disease and Hypertension in adult life

16. UTI in Childhood Always regarded as complicated
Treatment very effective
Recurrence is frequent following first UTI:
40% in females,
32% in males

17. Childhood UTI : Epidemiology
Prevalence is age and sex dependent
Overall F > M
In 2-10% of children 2 mo – 2 yrs of age with unexplained fevers

18. Incidence: age UTI diagnosed in 3% of prepubertal girls, and 1% boys
In children less than 1 year:
M (2.7%) > F (0.7%)

19. Incidence: sex Most male infections under 3 months
10 times more common in uncircumcised males
After first year 0.08% in boys
3-4% in girls until 6 years
Up to 8% of girls are affected by UTI

20. Access of bacteria
Haematogenous spread with bacteraemia in first 12 weeks
After 3 months by ascending seeding through urethra

21. Pathogens Most common: E. Coli Other: Proteus spp (in boys) Klebsiella
Pseudomonas
Enterococcus
Staphylococcus epidermidis
Staphylococcus aureus

22. Predisposing factors

23. Most commonly Constipation Vesico-ureteric reflux
Dysfunctional voiding- poor emptying
Infected periurethral area
Urinary stasis: PUJ, VUJ obstruction
Ureteral duplication and ectopic ureters

24. Causes for recurrent UTI
Vesico-ureteric reflux
Urinary stasis, constipation
Infected periurethral area
Infected atrophic kidney
Ureteral duplication and ectopic ureters
Infected urachal cysts, infected ureteral stump
Foreign bodies
Stones

25. Vesico-Ureteric Reflux

26. Vesico-ureteric Reflux
VUR demonstrated in 1-2% of healthy children
More prevalent in infants and young children
An intermittent phenomenon
Increased detection rate due to antenatal screening
Can be provoked by elevated voiding pressures

27. Vesico-ureteric Reflux and UTI
Reported in 30-50% of children with UTI
A large number still present after their first UTI
Reflux nephropathy is the cause for end-stage renal failure in 3-25% of children and 10-15% of adults

28. Evaluation of UTI

29. Presentation/Evaluation
History in infants and toddlers:
Fever,
irritability
Poor weight gain (FTT)
Smelly urine
Abdominal Pain
Dysuria, frequency, urgency
Haematuria
Enuresis and dysfunctional voiding
Constipation, thread worm infection, sore vulva

30. Presentation/Evaluation
History in children:
Fever
Abdominal Pain
(Flank/loin pain)
Dysuria, frequency, urgency
Haematuria
“smelly urine”
Enuresis and dysfunctional voiding
Constipation, thread worm infection, sore vulva

31. History/ evaluation History in Lower urinary tract infection:
irritability
Abdominal Pain
Dysuria, frequency, urgency
Haematuria
“smelly urine”
Enuresis and dysfunctional voiding
Constipation, thread worm infection, sore vulva

32. History in enuresis/ incontinence
Nocturnal symptoms:
Timing and onset of enuresis
Frequency of wetting (wet nights/week)
Times of wetting at night (one/several)
Amount of urine passed (small/large)
Daytime symptoms:
Urinary frequency (frequent/infrequent)
Urgency and urge incontinence
Quality of stream
Complete emptying?
Posturing (Vincent curtsey)

33. Evaluation Physical examination: full examination including:
Growth BP
genitalia
Urine test
imaging

34. Neuropathic Bladder
Sacral Agenesis

35. Laboratory assessment
Urine dipstick for Nitrites, Leukocytes
Urinalysis (clean catch sample)
Direct microscopy and gram staining
Culture and sensitivities

36. AAP and RCPCH guidelines for diagnosis of UTI in infants and young children
UTI should be ruled out in infants and children assessed to be sufficiently ill to require antibiotics treatment
Diagnosis of UTI requires a culture of urine

37. Imaging

38. Urinary Tract Imaging Plain Abdominal x-ray Ultrasound- any age
Micturating cystourethrogram < 1 year
Nuclear Imaging- any age
IVU
CT scan

39. Ultrasound Renal size and position
Scars, corticomedullary differentiation, cysts, masses, calcification, calculi
Pelvis and calyceal size and appearance
Pelvis-calyceal dilatation, urothelial thickening
Ureters
Dilatation, urothelial thickening, calculi
Bladder
outline, wall thickness, volume, residual volume

40. DMSA Renal cortical morphology Scars Overall function
Differential function
No information on VUR

41. MAG 3 Quantify renal excretory function Flow imaging PUJ obstruction
Indirect cystogram

42. MCUG: Bilateral VUR
DMSA: Left renal scarring

43. Imaging of urinary tract after first febrile UTI in Young children :
USS during acute illness of limited value
MCUG useful in young age group where AB prophylaxis considered to reduce re-infection and renal scarring
DMSA at presentation and 6 months later identifies renal scarring
Pittsburgh SM N E J M, Jan 2003

44. Complications of UTI

45. Complications Acute: Short term: Long term:
Systemic illness, sepsis, renal abscess
Short term:
Renal scarring, recurrence of UTI
Long term:
Hypertension
End-stage renal disease (overall 0.5%-5% of ESRD on dialysis have reflux nephropathy)

46. Renal scarring and VUR: International Reflux Study in Children
5 yr follow up 302 patients (10 yrs in 5/8 European centres)- serial IVU and DMSA
Grade III, IV, V VUR and symptomatic UTI
Medical vs Surgical treatment of VUR
New scars in 21 surgical and 19 medical
New scars mostly in children < 5years old
New scars more frequent in Grade IV
New scars in 2 females > 5 years
Olbing H et al, Ped Nephrol, Oct 2003

47. Complications of UTI in Children
Hypertension
Pyelonephritic scarring is the most common cause for hypertension in childhood
Prevalence of hypertension independent of the degree of scarring

48. Treatment

49. E. Coli Resistance trends
Ampicillin 39-45%
Trimethoprim-sulfamethoxazole 14-31%
Nitrofurantoin %
Fluoroquinolones (Ciprofloxacin) %
Mazzuli T, J Urol 2002

50. Drugs for Treatment TMP 4 mg/kg BD for 7-10 days
Cephalosporins (Cefuroxime, Cephalexin)
Gentamicin
Ciprofloxacin
Ampicillin?
Nitrofurantoin (over 3 mon)?

51. Duration of treatment
Uncomplicated UTI: > 5 days is associated with higher cure rates
Tran D et al, meta-analysis of 1279 patients
J Pediatr 2001
In Children < 2years of age: 7-14 days
AAP, Pediatrics 1999 and RCPCH appraisal

52. Drugs for prophylaxis Trimethoprim 2 mg/kg nocte
Cephalexin 12.5 mg/kg (up to 125 mg) nocte
Nitrofurantoin (over 3 mon) 1 mg/kg nocte

53. Cessation of prophylaxis
By age 4 years
When urinary continence achieved and infection free
Safe in patients in whom VUR fails to resolve
Thompson et al J Urol 2001

54. Surgery When? Anti-reflux open procedures: 95-98% success
Endoscopic subureteric injections: 75-90% success
Teflon- no longer approved by FDA (success 60-84%)
Collagen
Macroplastique
Deflux (Dextranomer/hyaluronic acid copolymer) 70% success
When?
Breakthrough UTI
Persistence of VUR
Parental preference

55. Treatment: Bladder Retraining
Aims at increasing functional bladder capacity and reduction in residual volume
2-3 hourly voiding
Double voiding
Increasing retention capacity
Isolated success in continence rate 35%

56. Prevention

57. Breast feeding
Lactoferrin and oligosaccharides act as analogues for microbial receptors
Prevents mucosal attachment
Lactoferrin can kill bacteria, viruses and fungi

58. Prevention Healthy voiding pattern Avoidance of constipation
Avoidance of local colonization
Circumcision?
Cranberry juice?
Probiotics?

59. Points to remember Accurate diagnosis of UTI
Low threshold to investigate in younger children (<4 years)
Appropriate treatment of acute events
Consider other problems when managing UTI

60. Points to remember The need to recognize the relationship between: VUR
Recurrent UTI’s
Voiding dysfunction
Renal scarring
Treatment should target each factor