ABSTRACT
Background Urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing bacteria are increasing worldwide. At our hospital, the number of children hospitalized with upper urinary tract infections (UUTI) caused by ESBL-producing Escherichia coli had been a major problem since 2016. However, since the start of the COVID-19 pandemic in 2020, the proportion of ESBL-producing E. coli has changed. This study reviewed the trends in admissions of children to the hospital with UUTI caused by E. coli. Methods This retrospective study included patients who were hospitalized in the pediatric department of Matsue Red Cross Hospital with UUTI caused by E. coli. Medical and hospital records were reviewed to assess patient characteristics, antimicrobial use density, and days of antibiotic therapy at the hospital from January 1, 2016 to December 31, 2022. Results Over the study period, 80 children were admitted to the hospital with their first episode of bacterial UUTI. The total number of children hospitalized in the pediatric department decreased. However, the proportion of children with UUTI per total number of hospitalized children remained stable over the study period. Urine sample analyses showed that the proportion of ESBL-producing E. coli decreased significantly in 2020 to 2022. Antimicrobial use density and days of therapy of oral third-generation cephems was significantly correlated with the proportion of UUTI caused by ESBL-producing E. coli in pediatric patients. Conclusion Effective hygiene measures and appropriate use of antibiotics especially, oral third-generation cephems, are effective for reducing the incidence of ESBL-producing bacterial infections.