1.1.1. Symptoms and signs

1.1.1.1.

Infants and children presenting with unexplained fever of 38°C or higher should have a urine sample tested within 24 hours. [2007]

1.1.1.2.

Infants and children with an alternative site of infection should not have a urine sample tested. When infants and children with an alternative site of infection remain unwell, urine testing should be considered after 24 hours at the latest. [2007]

1.1.1.3.

Infants and children with symptoms and signs suggestive of urinary tract infection (UTI) should have a urine sample tested for infection. Table 1 is a guide to the symptoms and signs that infants and children present with. [2007]

Table 1

Presenting symptoms and signs in infants and children with UTI.

1.1.2. Assessment of risk of serious illness

1.1.2.1.

The illness level in infants and children should be assessed in accordance with recommendations in the NICE guideline on fever in in under 5s. [2007]

1.1.3. Urine collection

1.1.3.1.

A clean catch urine sample is the recommended method for urine collection. If a clean catch urine sample is unobtainable:

• Other non-invasive methods such as urine collection pads should be used. It is important to follow the manufacturer’s instructions when using urine collection pads. Cotton wool balls, gauze and sanitary towels should not be used to collect urine in infants and children.
• When it is not possible or practical to collect urine by non-invasive methods, catheter samples or suprapubic aspiration (SPA) should be used.
• Before SPA is attempted, ultrasound guidance should be used to demonstrate the presence of urine in the bladder. [2007]

1.1.3.2.

In an infant or child with a high risk of serious illness it is highly preferable that a urine sample is obtained; however, treatment should not be delayed if a urine sample is unobtainable. [2007]

1.1.4. Urine preservation

1.1.4.1.

If urine is to be cultured but cannot be cultured within 4 hours of collection, the sample should be refrigerated or preserved with boric acid immediately. [2007]

1.1.4.2.

The manufacturer’s instructions should be followed when boric acid is used to ensure the correct specimen volume to avoid potential toxicity against bacteria in the specimen. [2007]

1.1.5. Urine testing

1.1.5.1.

For all diagnostic tests there will be a small number of false negative results; therefore clinicians should use clinical criteria for their decisions in cases where urine testing does not support the findings. [2007]

1.1.5.2.

Refer all infants under 3 months with a suspected UTI (see table 1) to paediatric specialist care, and

• send a urine sample for urgent microscopy and culture
• manage in line with the NICE guideline on fever in under 5s. [2017]

1.1.5.3.

Use dipstick testing for infants and children 3 months or older but younger than 3 years with suspected UTI.

• If both leukocyte esterase and nitrite are negative: do not start antibiotic treatment; do not send a urine sample for microscopy and culture unless at least 1 of the criteria in recommendation 1.1.6.1 apply.
• If leukocyte esterase or nitrite, or both are positive: start antibiotic treatment; send a urine sample for culture. [2017]

To find out why the committee made the 2017 recommendations on urine testing and how they might affect practice, see rationale and impact.

1.1.5.4.

The urine-testing strategy shown in table 2 is recommended for children aged 3 years or older^[1]. [2007]

1.1.5.5.

Follow the guidance in table 3 on interpreting microscopy results. [2007]

Table 2

Urine-testing strategies for children 3 years or older.

Table 3

Guidance on the interpretation of microscopy results.

1.1.6. Indication for culture

1.1.6.1.

Urine samples should be sent for culture:

• in infants and children who are suspected to have acute pyelonephritis/upper urinary tract infection (see 1.1.8.1)
• in infants and children with a high to intermediate risk of serious illness
• in infants under 3 months
• in infants and children with a positive result for leukocyte esterase or nitrite
• in infants and children with recurrent UTI
• in infants and children with an infection that does not respond to treatment within 24–48 hours, if no sample has already been sent
• when clinical symptoms and dipstick tests do not correlate. [2017]

1.1.7. History and examination on confirmed UTI

1.1.7.1.

The following risk factors for UTI and serious underlying pathology should be recorded:

• poor urine flow
• history suggesting previous UTI or confirmed previous UTI
• recurrent fever of uncertain origin
• antenatally diagnosed renal abnormality
• family history of vesicoureteric reflux (VUR) or renal disease
• constipation
• dysfunctional voiding
• enlarged bladder
• abdominal mass
• evidence of spinal lesion
• poor growth
• high blood pressure. [2007]

1.1.8. Clinical differentiation between acute pyelonephritis/upper urinary tract infection and cystitis/lower urinary tract infection

1.1.8.1.

Infants and children who have bacteriuria and fever of 38°C or higher should be considered to have acute pyelonephritis/upper urinary tract infection. Infants and children presenting with fever lower than 38°C with loin pain/tenderness and bacteriuria should also be considered to have acute pyelonephritis/upper urinary tract infection. All other infants and children who have bacteriuria but no systemic symptoms or signs should be considered to have cystitis/lower urinary tract infection. [2007]

1.1.9. Laboratory tests for localising UTI

1.1.9.1.

C-reactive protein alone should not be used to differentiate acute pyelonephritis/upper urinary tract infection from cystitis/lower urinary tract infection in infants and children. [2007]

1.1.10. Imaging tests for localising UTI

1.1.10.1.

The routine use of imaging in the localisation of a UTI is not recommended. [2007]

1.1.10.2.

In the rare instances when it is clinically important to confirm or exclude acute pyelonephritis/upper urinary tract infection, power Doppler ultrasound is recommended. When this is not available or the diagnosis still cannot be confirmed, a dimercaptosuccinic acid (DMSA) scintigraphy scan is recommended. [2007]

1.2.2. Prevention of recurrence

1.2.2.1.

Dysfunctional elimination syndromes and constipation should be addressed in infants and children who have had a UTI. [2007]

1.2.2.2.

Children who have had a UTI should be encouraged to drink an adequate amount. [2007]

1.2.2.3.

Children who have had a UTI should have ready access to clean toilets when required and should not be expected to delay voiding. [2007]

1.2.3. Antibiotic prophylaxis

1.2.3.1.

Antibiotic prophylaxis should not be routinely recommended in infants and children following first-time UTI. [2007]

1.2.3.2.

This recommendation has been replaced by the NICE guideline on urinary tract infection (recurrent): antimicrobial prescribing.

1.2.3.3.

Asymptomatic bacteriuria in infants and children should not be treated with prophylactic antibiotics. [2007]

Bacteriuria

Bacteria in the urine with or without urinary tract infection.

Pyuria

White cells in the urine.

Why this is important

UTI and VUR in young children have been shown to be associated with both congenital and acquired renal damage. Progressive scarring is well documented in children with high grade VUR and recurrent UTI. Scarring has been associated with severe hypertension, proteinuria, complications in pregnancy and progression to established renal failure. These risks are likely to be greater in children with bilateral renal parenchymal defects. However, the frequency and magnitude of these risks for children with unilateral and bilateral renal damage are unclear. Knowledge of the risk of serious or progressive complications would be useful to determine the management of children with first-time and recurrent UTIs.

Why the committee made the 2017 recommendations

Evidence showed that a positive urine dipstick test for leukocyte esterase or nitrite in children 3 months or older but younger than 3 years greatly increases the likelihood of finding a positive urine culture. Sending only positive samples for culture offered a better balance of benefits and costs for these children than prescribing antibiotics and urine culture for all children. The committee agreed that there are concerns about sepsis in infants under 3 months with suspected UTI, and usual practice is referral rather than the GP managing symptoms. So the committee recommended that all children under 3 months should be referred to specialist paediatric care and have a urine sample sent for urgent microscopy and culture. In children aged 3 months or older but younger than 3 years, symptoms are easier to identify, and antibiotics should only be started if a dipstick test is positive for either or both leukocyte esterase or nitrite. Children in this age group with a positive dipstick test should also have a urine sample sent for culture.

How the 2017 recommendations might affect practice

Recommending dipstick testing in infants and children aged 3 months or older but younger than 3 years clarifies the role of dipstick testing in this age group and encourages immediate diagnosis and treatment in primary care. The committee believe the new recommendations will provide concise and clear guidance for health care professionals, more efficient diagnosis for infants and children, and cost savings and a reduced burden on laboratories by reducing the number of urine samples sent for culture.