Urinary Tract Infection in Childhood

Definition
Significant bacteriuria + inflammation


Aetiology
Infecting organism

• E. Coli in 80%, followed by Proteus & Pseudomonas
• Gram-ve  : Klebsiella, Proteus, Enrerobacter, Citrobacter
• Gram+ve : Staph saprophyticus, Enterococcus, and rarely S.aureus

Incomplete bladder emptying

• infrequent voiding, resulting in bladder
• vulvitis
• hurried micturition
• obstruction by loaded rectum from constipation
• neuropathic bladder
• vesicoureteric reflux

Vesicoureteric reflux (VUR)

• a developmental anomaly: ureters are displaced laterally and enter directly into bladder rather than at an angle.
• Severe cases maybe associated with renal dysplasia
• Familial, 30-50% chance of occuring in 1st degree family
• may occur with bladder pathology eg neurogenic bladder, urethral obstruction, or temporaly after UTI
• Mild: reflux into the lower end of an undilated ureter during micturition
• Severe:  reflux during bladder filling and voiding, with a distended ureter, renal pelvis and clubbed calyces - maybe associated with intrarenal reflux (IRR) which is associated with renal scarring if UTIs occur
• Reflux + ureteric dilatation increased risk of pyrlonephritis, high pressure and renal damage

Epidemiology
In children <2y, overall prevalence of UTI =5% in febrile infants
Caucassian children have 2-4 fold higher than African-American
Females 2-4 fold higher than circumcised males
Caucassian female with a Temperature > 39C, have UTI prevalence of 16%

Presentation
Varies with age

Infancy	Childhood
Fever Lethargy or irritability Vomitting, diarrhoea Poor feeding/ failure to thrive Prolonged neonatal jaundice Septicaemia Febrile convulsion (>6 months)	Dysuria & frequency Fever with or without rigors Lethargy & anorexia Vomitting, diarrhoea Abdominal or loin pain Febrile convulsion (not to be confused with rigors) Recurrence of enuresis

DDx

• Neonates: sepsis
• Toddlers : Gastroenteritis, intussusception, bubble bath urethhritis
• Older children : renal stones, ureteropelvic junction obstruction, infectious urethritis
• Idiopathic hypercalciuria
• Dysfunctional voiding
• Diabetes Insipidus
• Diabetes melitus
• Musculoskeletal flamk pain
• Contaminated specimen
• Vaginitis

Investigation
Antenatal diagnosis of urinary tract anomalies

Collection of Samples
For the child in nappies

• absorbent pads
• a 'clean-catch' sample into a waiting clean pot when the nappy is removed (easier in boys)
• an adhesive plastic bag applied to perineum (contamination)
• suprapubic aspiration (SPA) with US guidance - in severely ill infant < 1y.o
• catheter sample

For older child

• mid-stream urine - contamination from under foreskin or urine reflux into the vagina

Culture

• >105 per ml gives a 90% probability of infection
• If the same result is found in a 2nd sample : 95%

Management