How best to diagnose urinary tract infection in preschool children in primary care?

Accurate and timely diagnosis of urinary tract infection (UTI) in young children presenting to primary care is important because appropriate treatment may alleviate suffering and help prevent long term sequelae such as renal scarring, poor renal growth, recurrent pyelonephritis, impaired glomerular function, hypertension, end stage renal disease, and pre-eclampsia. 2 The prevalence of renal scarring in the general population is unknown, but a systematic review of studies, largely conducted in secondary care, showed 15% of children with an initial episode of UTI had evidence of renal scarring on follow-up dimercaptosuccinic acid (DMSA) scanning, and there was an 8% incidence of UTI recurrence per year. Among consultations for illness episodes in children aged under 5 years in the UK, approximately 40% comprise infectious diseases and respiratory episodes, while about 10% of presentations comprise non-specific symptoms. Thus identifying which children have a significant UTI (which often also presents with non-specific symptoms) is a key challenge for primary care clinicians. The diagnosis is further hampered because young children cannot clearly articulate symptoms; when children wear nappies, parents are not aware of the classic dysuria and frequency symptoms as experienced by adults; and obtaining an adequate urine sample can be frustrating, time consuming, and costly. The precise prevalence of UTI among all acutely unwell children presenting to primary care is unclear. One systematic review of 10 studies, eight of which were conducted in hospital emergency departments, one in US paediatricians’ offices, and one in an army medical centre, estimated UTI prevalence at 7%. A large Australian emergency department study published in 2010 found a prevalence of 3.4% in children presenting with a febrile illness. We identified only one small exploratory study conducted in general practitioner/family physician practices, which found a prevalence of 4%. It is not surprising then that the diagnosis of UTI is often delayed and may be missed in up to 50% of children presenting to primary care, sometimes due to symptoms being incorrectly attributed to other causes (such as otitis media). The pressure to reduce antibiotic prescribing may reduce the serendipitous treatment of undiagnosed UTI and the consequent prevention of renal sequelae, making accurate diagnosis now even more important than ever. What is the evidence of the uncertainty?