The role of bacterial adhesins in the outcome of childhood urinary tract infections.

Abstract

Objectives: To compare the efficacy of 3-day vs 10-day treatment with a combination of amoxicillin and clavulanate potassium for children with uncomplicated urinary tract infections and to determine the role of host factors, including vesicoureteral reflux, and of bacterial virulence factors, including adhesins, in treatment outcome.

Design: Randomized, double-blind, controlled trial.

Setting: A pediatric infectious diseases clinic at an urban medical center.

Patients: Thirty-seven children with uncomplicated urinary tract infections.

Interventions: Treatment with 3 days or 10 days of antibiotics at a dosage of 20 mg/kg per day of amoxicillin and 5 mg/kg per day of clavulanate potassium in three divided doses.

Measurements and main results: The success rate for 10-day treatment was 82% (14/17) compared with 55% (11/20) for 3-day treatment (P = .09). Among the 35 patients infected with Escherichia coli, all 10 patients infected with adhesin-negative isolates were treated successfully regardless of the duration of treatment, whereas only 14 (56%) of the 25 infections involving adhesin-positive isolates were clinically cured (P = .015). Two of the three failures in the 10-day treatment group were in patients with reflux.

Conclusions: We conclude that 3-day treatment with amoxicillin and clavulanate is insufficient for afebrile childhood urinary tract infections and that both bacterial and host factors affect treatment outcome.