Clinical and Microbiologic Predictors of Progression to Infection Among Children With Enteric Colonization by Carbapenemase-producing Enterobacterales.

BACKGROUND: Carbapenemase-producing Enterobacterales (CPE) colonization is rising globally, yet data on pediatric patients and the risk of progression to infection remain scarce. This study identified clinical/microbiologic profiles and risk factors for progression to infection in colonized children. METHODS: This retrospective cohort study included children colonized by CPE at a tertiary pediatric hospital in Brazil (August 2019-December 2024). Colonization was defined as a CPE-positive rectal swab without clinical signs of infection, while infection was defined as illness caused by the bacteria. Demographic, clinical and microbiologic data were evaluated over a 12-month postcolonization follow-up. Cox proportional hazard models assessed the association between risk factors and the time to CPE infection. RESULTS: We included 521 CPE colonization episodes in 466 patients (82% with comorbidities; median age 8.8 months [interquartile range: 2.6-64.6]). Klebsiella pneumoniae predominated. Isolates produced Klebsiella pneumoniae carbapenemase (KPC) (56.9%), New Delhi metallo-β-lactamase (31.3%) or both (11.6%). Progression to infection by the same carbapenemase type occurred in 55 patients (11.8%). Independent risk factors were age 6 months or under (hazard ratio [HR]: 2.19, 95% confidence interval [CI]: 1.27-3.79), KPC colonization (HR: 2.00, 95% CI: 1.05-3.81), preexisting liver disease (HR: 2.67, 95% CI: 1.03-6.92) and respiratory disease (HR: 1.95, 95% CI: 1.07-3.57) and the presence of invasive devices (HR: 2.15, 95% CI: 1.16-3.98). Infection-related mortality was 10.9%. CONCLUSIONS: CPE colonization is an emerging threat in vulnerable pediatric populations. Progression to infection is primarily driven by KPC production, chronic comorbidities and invasive devices.