Trends in antibiotic resistance of urinary tract infections in young children, 2010-2023.

Background: Urinary tract infections (UTI) are the leading cause of severe bacterial infection in children under 24 months. Increasing antimicrobial resistance, particularly to third-generation cephalosporins, is a growing concern. This study examines recent resistance trends in young children with UTI in Korea.

Methods: A retrospective study was conducted on children under 24 months who presented with UTI to three university hospitals in Korea between 2010 and 2023. Children diagnosed with UTI and/or acute pyelonephritis with gram-negative bacteria identified in urine cultures were included. Antibiotic susceptibility data of antibiotics commonly used to treat pediatric UTI were collected, focusing on third-generation cephalosporins. Trends in resistance were analyzed according to age group, causative organism, and the presence of congenital anomalies of the kidney and urinary tract.

Results: A total of 10,029 children were included, with a mean age of 4.0 months (IQR, 2.3-6.6 months); 67.9 % were male, and Escherichia coli accounted for 84 % of isolates. Resistance to cefotaxime increased significantly from around 10 % in the early 2010s to over 30 % after 2020. This increasing trend was consistent regardless of age group, causative organism, or presence of congenital anomalies of the kidney and urinary tract, although it showed a decreasing trend after 2021.

Conclusions: There has been a significant rise in resistance to third-generation cephalosporins among young children with UTI in Korea over the past decade. These findings suggest a need to reconsider the empirical use of these antibiotics and consider alternative treatments to effectively manage UTI and prevent kidney scarring in Korean children.