Risk factors for recurrent urinary tract infection in preschool children

Objective: Children with urinary tract infections (UTI) are at risk of renal scarring which may lead to impaired renal function and hypertension. This study examines the risk factors that predispose to recurrent UTI in children and the role of recurrent UTI in renal scarring. Methodology: A group of 290 children under 5 years of age with a first symptomatic UTI were studied. Micturating cystourethrogram and dimercaptosuccinic acid (DMSA) renal scintigraphy were performed at entry, and DMSA was repeated 1 year later. Two hundred and sixty-one children (90%) were followed up at 1 year. Results: There were 46 confirmed recurrent infections in 34 children, a recurrence rate of 12%. Multiple recurrence occurred in 14/34 (34%) children. Age of less than 6 months on entry independently predicted for recurrent UTI (odds ratio (OR): 2.9)). Compliance with prophylactic antibiotics fell throughout the year of follow up. Vesicoureteric reflux (VUR) was present in 14/34 (34%) or the group with recurrent UTI, 69/256 (27%) without recurrence. Urinary tract infection was significantly associated with bilateral and intrarenal reflux; grade 3-5 reflux independently predicted for recurrent UTI (OR: 3.5). Recurrent UTI was significantly associated with high grade DMSA defects on entry, renal parenchymal defects at 1 year follow up, and new defects at 1 year. Conclusions: The independent risk factors for recurrent UTI identified by this study were an age of less than 6 months at the index UTI and grade 3-5 VUR. These findings suggest more selective targeting may minimize problems associated with prophylaxis and improve outcomes for children with urine infection.