Infant urinary tract infection in Sweden - A national study of current diagnostic procedures, imaging and treatment.

Background: Urinary tract infection (UTI) in infants is a common, potentially life-threatening bacterial infection, and must be managed carefully through the entire chain of care from diagnosis, choice of treatment, follow-up and risk stratification of future complications. This Swedish nationwide study of infant UTI was conducted to evaluate the current management of infant UTI, yield of investigations and the Swedish UTI guidelines' ability to detect abnormalities of importance in the urinary tract.

Methods: Infants < 1 year with a first episode of UTI were included in a prospective multicenter study. Treatment and follow-up were provided by local pediatricians. Clinical and laboratory findings and imaging results were reported to the coordinating center. The current management and results were compared with a previous Swedish study.

Results: One thousand three hundred six infants were included. Urine sampling was performed with clean catch technique in 93% of patients. Initial oral antibiotic treatment was used in 63%, predominantly third generation cephalosporines. Permanent kidney abnormalities were found in 10% and dilating vesicoureteral reflux (VUR) in 8%. Higher rates of male gender, non-E. coli infection and ultrasound dilatation were seen in infants < 1 month. UTI recurrences were reported in 18%.

Conclusions: Infant UTI is still generating a considerable amount of follow-up examinations. There is a significant shift towards clean catch as the main urine sampling method. Voiding cystourethrography is performed less frequently reducing the findings of low grade VUR. The incidence of renal scarring is comparable with earlier studies which suggests that the Swedish guidelines are able to identify individuals with risk for long-term complications.