Epidemiology and Risk Factors of Pediatric Clostridioides difficile Infection: A Nationwide Claims-based Comparison With Adults in Japan.

Background: Pediatric Clostridioides difficile infection (CDI) is a growing concern, yet nationwide data from Japan are scarce. Current guidelines often discourage CDI testing in infants due to a presumed low incidence of clinical disease. We aimed to characterize the epidemiology and risk factors of pediatric CDI in Japan, focusing on age-specific patterns and community-onset cases.

Methods: We performed a retrospective analysis using the Japan Medical Data Center claims database from 2013 to 2022. CDI cases were defined by the presence of both diagnostic testing and anti-CDI treatment within 7 days. Episodes that relapsed within 8 weeks were excluded. CDI onset setting was classified according to CDC/NHSN criteria. Risk factors were evaluated by age and onset setting.

Results: Of the 4090 CDI cases, 284 were pediatric. The incidence in children aged 0-2 years was comparable to that in older children, challenging current assumptions. Risk factor profiles varied by age group and setting, with inflammatory bowel disease being a prominent risk factor in children (28.9% vs. 14.8% in adults/older adults), particularly in adolescents (43.5%). Critically, nearly half of community-onset pediatric CDI cases had no prior antibiotic exposure.

Conclusion: This first large-scale study of pediatric CDI in Japan revealed that CDI can occur in children without prior antibiotic exposure, particularly in community settings. These findings support consideration of revisions to management strategies for pediatric CDI.