See also

Febrile child
Sepsis
SPA
Urinary samples

Key points

1. Signs and symptoms of urinary tract infection (UTI) can be non-specific in young children
2. Collecting urine to exclude UTI is not required if there is another clear focus of fever and the child is not unwell
3. Urinary dipstick is a useful screening test, but a positive urine culture with pyuria confirms the diagnosis
4. Oral antibiotics are appropriate for most children with UTI. Children who are seriously unwell and most infants under 3 months usually require IV antibiotics
5. Seriously unwell children, those with renal impairment, and boys <3 months of age should have a renal ultrasound prior to discharge to exclude renal tract obstruction

Background

• Signs and symptoms of UTI can be non-specific, and overlap with common viral illnesses, especially in younger children
• A urine sample is required to diagnose or exclude UTI where clinically suspected
• Consider UTI if fever without focus persists after 48 hours in young children

Assessment

History

• Infants and pre-verbal children often present with non-specific symptoms such as fever, vomiting, poor feeding, lethargy and irritability
• Older children may present with more typical symptoms such as dysuria, urinary frequency, lower abdominal and loin pain
• Ask about previous UTI

Examination

• Examination may be normal in UTI other than the presence of fever
• Lower abdominal or loin tenderness may be present
• Non-specific findings include dehydration and lethargy  

Assessment of severity

• Clinical distinction between lower and upper UTI can be difficult, especially in younger children
• Cystitis is suggested by features such as dysuria, frequency, urgency and lower abdominal discomfort
• Pyelonephritis is suggested by systemic features such as fever, malaise, vomiting and loin tenderness

Management

Investigation

Children with suspected UTI should have a urine sample collected; dipstick and microscopy screening can guide initial management. Check culture results after 24 hours to confirm or adjust management as appropriate

Urine samples should be collected prior to starting antibiotics (unless the child is seriously unwell and requires immediate IV therapy)

• Older children able to void on request can provide a midstream urine sample
• For younger pre-continent children, a clean catch is often suitable. Catheter or SPA may be required for seriously unwell infants

Urine Collection

• The perineal/genital area should be cleaned with saline-soaked gauze for 10 seconds before collecting midstream or clean catch urine
  
  
• Midstream urine (MSU): preferred method for toilet-trained children who can void on request — contamination rate 25%
  
  
• Clean catch: appropriate for pre-continent children who cannot void on request, but are not seriously unwell (yield may be improved by gently rubbing child’s suprapubic area with gauze soaked in cold fluid, see urine tests) — contamination rate 25%
  
  
• Suprapubic aspirate (see SPA): gold standard — contamination rate 1%
  
  
• In/out catheter: useful if there is little urine in the bladder, such as after failed clean catch or SPA (discard first few drops of urine if possible to reduce contamination) — contamination rate 10%
  
  
• Bag urine: not recommended for culture due to high false positive rates — contamination rate 50%

Urine dipstick

• Urine dipstick is a useful screening test to guide initial management
• The presence of leucocytes and nitrites is suggestive of a UTI. See notes section below
• Dipstick results are less reliable in neonates and young infants, particularly due to false negatives

Urine Microscopy and Culture

• Laboratory microscopy can complement dipstick results to guide initial management 
• Bacteria and leucocytes on microscopy are suggestive of UTI. See notes section below
• Epithelial cells (squames) suggest skin contamination and a poorly collected sample. Consider recollection
• A positive culture with sufficient growth and pyuria confirms UTI
• Growth of a single organism at >10⁸ CFU/litre (>10⁵ CFU/mL) from any collection method suggests infection
• Growth of a single organism at lower counts of 10^6-8 CFU/litre (>10^3-5 CFU/mL) from catheter or SPA urine suggests infection, and from clean catch or MSU may indicate early infection
• Growth of any amount from SPA suggests infection

Other investigations

• Check renal function and consider renal ultrasound if the child is seriously unwell, or not responding to appropriate therapy after 48hrs
• Consider blood culture and lumbar puncture for unwell infants less than 4 weeks old, or if sepsis or meningitis is suspected at any age

Treatment

• Oral antibiotics are usually appropriate
• Any child who is seriously unwell, and most infants under 3 months, should be admitted for initial IV antibiotics
• 3–7 day course for children with cystitis
• 7–10 day course for children with pyelonephritis

Oral treatment

Cefalexin 33 mg/kg (max 500 mg) oral bd 

For pyelonephritis: cefalexin 45 mg/kg (max 1.5 g) oral tds

IV treatment

• Do not delay antibiotic therapy for a child who is seriously unwell, even if a urine sample has not been obtained
• Recommended empiric IV antibiotics: gentamicin + benzylpenicillin. See Antibiotic Guideline
  • Check gentamicin levels and renal function before third dose if continuing gentamicin beyond 48 hours
• Switch to oral antibiotics when clinically improved and/or as soon as tolerating oral antibiotics

Follow up

• Seriously unwell children, those with renal impairment, and boys <3 months of age should have a renal ultrasound prior to discharge
• Other children do not require an ultrasound for a first UTI; a non-urgent renal ultrasound should be arranged for children who have recurrent UTIs
• Routine antibiotic prophylaxis after simple UTI is not required
• Specialist follow-up should be arranged for children with recurrent UTI or known renal anomalies

Consider consultation with local paediatric team when

• Child under 6 months of age
• Child has known renal tract anomalies or not responding to initial therapy
• Treating any child who is seriously unwell

Consider transfer when

Any child requiring care beyond the level of comfort of the treating hospital

For emergency advice and paediatric or neonatal ICU transfers, see Retrieval Services.

Consider discharge when

Tolerating oral fluids and antibiotics

Parent information

Kids Health Info

Urinary tract infection  

Urine Tests 

New South Wales Children's Hospitals Network

Urinary tract infection in children

Queensland Children's Health

Urinary tract infection 

How to collect a clean urine specimen

Additional notes

Interpreting urine test results

• Blood and protein are not reliable markers of UTI
• Nitrites are not produced by all urinary organisms, so the absence of nitrites on dipstick does not exclude UTI
• Pyuria (leucocytes) can occur with other febrile illnesses, so pyuria alone on dipstick/microscopy does not confirm UTI
• Pyuria may be absent in early infection or very young children
• Pyuria and bacteria seen on microscopy are suggestive of UTI, but a positive culture is required to confirm the diagnosis
• Pure growth at low colony counts (CFU) may indicate early infection. Consider sample recollection or empiric treatment if the child remains unwell

Last updated July, 2019