Urinary Tract Infection

Question 1

What is the difference between cystitis and pyelonephritis

Answer 1

Cystitis (Lower UTI) = bladder and urethra
Pyelonephritis (upper UTI) = renal pelvis and kidneys

Question 2

What defines atypical UTI

Answer 2

Serious illness
Poor urine flow
Abdominal or bladder mass
Raised creatinine
Sepsis
Failure to respond to treatment with suitable antibiotics within 48 hours
Infection with non-E. Coli organisms

Question 3

What defines recurrent UTI

Answer 3

≥2 episodes of UTI with acute pyelonephritis
1 episodes of UTI with acute pyelonephritis + ≥1 episode of UTI with cystitis
≥3 episodes of UTI with cystitis

Question 4

What is the aetiology of UTI

Answer 4

Predominantly bacterial:
- E. Coli (80-90% of paediatric UTIs)
- Proteus mirabilis (30% of boys with uncomplicated cystitis)
- Staphylococcus saprophyticus (adolescents of both sexes with acute UTI)
- Klebsiella aerogenes
- Enterococcus
- Pseudomonas species, Serratia marcescens, Citrobacter species, and Staphylococcus epidermidis
Viral: adenovirus
Candida (immunosuppressed)

Question 5

What are the risk factors for UTI

Answer 5

Younge age (<1 yo)
Female sex (but <3 months, it is more common in uncircumcised boys)
Previous UTI
Voiding dysfunction (structural abnormalities, neurogenic bladder, voluntary withholding of urine, chronic constipation, indwelling foreign bodies)
Vesicoureteral reflux (VUR)
FHX of VUR
Sexual activity
Immunosuppression

Question 6

What is the epidemiology of UTIs in children

Answer 6

Around 1 in 10 girls and 1 in 30 boys will have had a UTI by the age of 16
Uncircumcised boys in the first year of life have a greater than 8-fold higher incidence of UTI compared to girls or circumcised boys.
Prevalence of UTI is higher among white than among black infants
Breastfeeding is protective, especially in girls

Question 7

What are the symptoms of UTIs in children

Answer 7

<3 months: Fever, vomiting, lethargy, irritability, poor feeding, FTT
>3 months:
- Dysuria, frequency, dysfunctional voiding, changes to continence
- Fever
- Abdominal pain, loin tenderness
- Vomiting
- Poor feeding and fluid intake
± haematuria, offensive cloudy urine

Question 8

What are the features of pyelonephritis

Answer 8

Either:
- Fever of ≥38 AND bacteriuria
- Fever <38 AND loin/pain tenderness AND bacteriuria

Question 9

When should a urine sample for MC&S be sent

Answer 9

<3yo
High/intermediate risk of serious illness
Symptoms suggestive of pyelonephritis
Previous UTI
No response to treatment
Urine dip is leukocyte esterase + but nitrite -
For children <3 months who have been referred

Question 10

What investigations should be done for UTI in children

Answer 10

Urine dip: leukocytes +, nitrites +
Urine sample for MC&S: Positive culture
BM

Atypical or recurrent UTI:
- US urinary tract
- Dimercaptosuccinic acid scintigraphy (DMSA) scan

Question 11

How are urine samples taken in children

Answer 11

Infants and toddlers: clean catch urine (CCU)
- Gentle suprapubic cutaneous stimulation using gauze soaked in cold fluid
- Potties cleaned in hot water with washing up liquid may be used.
- Other non-invasive methods include urine collection pads.
- Do not use cotton wool balls, gauze or sanitary towels.
Otherwise: catheter OR suprapubic aspiration (SPA)

Question 12

What is the management for typical UTI

Answer 12

> 3 months with pyelonephritis, no vomiting → PO cefalexin 7-10 days

Abx: oral trimethoprim for 3 days (5 days if male)
(second: nitrofurantoin, third: amoxicillin)
Advice: must complete treatment, use paracetamol for pain relief, adequate fluid intake, access to clean toilets, do not delay voiding
Safety net: 48hrs with no response

+ follow up

Question 13

What is the management for pyelonephritis

Answer 13

Urgent referral to paediatric specialist
<3 months or vomiting → admit → IV co-amoxiclav 5-7 days

Not vomiting → oral cefalexin for 7-10 days
Alternative: co-amoxiclav
+ follow up

Question 14

What is the management for atypical or recurrent UTI

Answer 14

Arrange Ultrasound of the kidneys and pelvis AND DMSA scan
First line: Behavioural and personal hygiene measures
Second line: Consider daily antibiotic prophylaxis e.g. Trimethoprim, Nitrofurantoin, Cefalexin, Amoxicillin

+ review every6 months

Question 15

What are the complications of UTI in childhood

Answer 15

Renal scarring/damage
- Almost always preceded by pyelonephritis
- More common in children with VUR
Hypertension
Bacteriuria and hypertension in pregnancy (pre-eclampsia)
Renal insufficiency and failure
Recurrency (RF: poor flow, renal abnormality, FHx VUR/renal disease, constipation, enlarged bladder, abdominal mass, spinal lesion)

Question 16

What is the prognosis for UTIs in children

Answer 16

Prognosis is good
40-70% of children will have an episode of recurrence, girls are more likely to have a recurrence
Recurrence rate increases with age
Progression of renal dysfunction is likely in those with urinary tract comorbidity
Rarely, long-term complications may occur

Question 17

What is the follow up for UTI in children

Answer 17

<6 months with good response → US in 6 weeks
Atypical → US during infection, DMSA 4-6 months + MCUG

Question 18

What investigations should be done for recurrent UTI

Answer 18

<6 months: US during infection
>6 months: US 6 wks after
DMSA within 6 months
MCUG <6 months

Question 19

What should be done for the following dipstick results:
Leukocytes+ Nitrites +
L - N -
L - N +
L + N -

Answer 19

Leukocytes+ Nitrites +: start Abx
L - N - : consider other DDx
L - N + : start Abx
L + N - : send for MC&S