Urinary Tract Infections in Children

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Urinary Tract Infections in Children

• Dr. Rim El-Rifai
• Consultant Paediatrician
• QMHC

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Outline of talk

• Cases
• Introduction and definitions
• Evaluation of UTI
• Management
• Summary

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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 PUOs for 2 days at a time
• No abnormal physical findings on examination

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investigations

• Ultrasound scan KUB
• 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?

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3 weeks old girl

• Initial presentation to AE vomiting
• Treated with IV ABs
• 2 urine samples had mixed growth but gt 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

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Investigations

• KUB USS normal
• Abdo. USS Pyloric Stenosis
• MCUG and DMSA awaited

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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

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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 gt 10
• Pure growth of organisms gt 107

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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

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Pyuria

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

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Sites of origin of UTI

• Acute pyelonephritis
• acute bacterial infection of the kidney
• Fever, rigors
• Flank pain
• Bacteriuria and pyuria
• Unwell child, usually febrile

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Sites of origin of UTI

• Bacterial Cystitis Inflammation of the bladder
• Abrupt onset of dysuria
• Frequency
• Urgency
• Suprapubic pain
• Non-bacterial cystitis chemical

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Sites of origin of UTI

• Urethritis
• Inflammation of the urethra
• Symptoms difficult to differentiate from cystitis
• Seen in girls with vulvovaginitis

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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

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UTI in Childhood

• Always regarded as complicated
• Treatment very effective
• Recurrence is frequent following first UTI
• 40 in females,
• 32 in males

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Childhood UTI Epidemiology

• Prevalence is age and sex dependent
• Overall F gt M
• In 2-10 of children 2 mo 2 yrs of age with
  unexplained fevers

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Incidence age

• UTI diagnosed in 3 of prepubertal girls, and 1
  boys
• In children less than 1 year
• M (2.7) gt F (0.7)

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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

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Access of bacteria

• Haematogenous spread with bacteraemia in first 12
  weeks
• After 3 months by ascending seeding through
  urethra

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Pathogens

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

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Predisposing factors
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Most commonly

• Constipation
• Vesico-ureteric reflux
• Dysfunctional voiding- poor emptying
• Infected periurethral area
• Urinary stasis PUJ, VUJ obstruction
• Ureteral duplication and ectopic ureters

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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

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Vesico-Ureteric Reflux
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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

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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

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Evaluation of UTI
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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

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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

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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

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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)

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Evaluation

• Physical examination full examination including
• Growth
• BP
• genitalia
• Urine test
• imaging

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Neuropathic Bladder
Sacral Agenesis
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Laboratory assessment

• Urine dipstick for Nitrites, Leukocytes
• Urinalysis (clean catch sample)
• Direct microscopy and gram staining
• Culture and sensitivities

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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

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Imaging
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Urinary Tract Imaging

• Plain Abdominal x-ray
• Ultrasound- any age
• Micturating cystourethrogram lt 1 year
• Nuclear Imaging- any age
• IVU
• CT scan

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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

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DMSA

• Renal cortical morphology
• Scars
• Overall function
• Differential function
• No information on VUR

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MAG 3

• Quantify renal excretory function
• Flow imaging
• PUJ obstruction
• Indirect cystogram

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MCUG Bilateral VUR
DMSA Left renal scarring
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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
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Complications of UTI
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Complications

• Acute
• 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)

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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 lt 5years old
• New scars more frequent in Grade IV
• New scars in 2 females gt 5 years

• Olbing H et al, Ped Nephrol, Oct 2003

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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

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Treatment
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E. Coli Resistance trends

• Ampicillin 39-45
• Trimethoprim-sulfamethoxazole 14-31
• Nitrofurantoin 1.8-16
• Fluoroquinolones (Ciprofloxacin) 0.7-10
• Mazzuli T, J Urol 2002

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Drugs for Treatment

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

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Duration of treatment

• Uncomplicated UTI gt 5 days is associated with
  higher cure rates
• Tran D et al, meta-analysis of 1279 patients
• J Pediatr 2001
• In Children lt 2years of age 7-14 days
• AAP, Pediatrics 1999 and RCPCH appraisal

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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

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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

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Surgery

• 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

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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

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Prevention
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Breast feeding

• Lactoferrin and oligosaccharides act as analogues
  for microbial receptors
• Prevents mucosal attachment
• Lactoferrin can kill bacteria, viruses and fungi

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Prevention

• Healthy voiding pattern
• Avoidance of constipation
• Avoidance of local colonization
• Circumcision?
• Cranberry juice?
• Probiotics?

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Points to remember

• Accurate diagnosis of UTI
• Low threshold to investigate in younger children
  (lt4 years)
• Appropriate treatment of acute events
• Consider other problems when managing UTI

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Points to remember

• The need to recognize the relationship between
• VUR
• Recurrent UTIs
• Voiding dysfunction
• Renal scarring
• Treatment should target each factor

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