Abstract: Background: Carbapenem-resistant organism (CRO) infections have been increasing in recent years and associated with significant, severe infection and mortality. Objective: To assess the risk factors and prognosis of CRO infections in children with acute leukemia and to provide reference for its prevention. Design: Case-control study. Methods: The data of in-patients with acute leukemia, except for acute promyelocytic leukemia, infected by CRO or carbapenem-susceptible organism (CSO) were recruited from Department of Hematological Oncology at Children's Hospital of Shanghai, Shanghai Jiaotong University School of Medicine between January 2012 and December 2019 to retrospectively analyze their clinical characteristics, prognosis factors and rate of severe infections. Main outcome measures: Risk factors for CRO infection and the incidence of severe infection within 72-hour of empirical anti-infection treatment. Results: A total of 101 samples (91 patients) with Gram-negative organism infections were included into the study, including 76 CSO and 25 CRO. There were 67 cases of acute lymphoblastic leukemia (66.3%) and 34 cases of acute myeloid leukemia (33.7%). Multivariate logistic analysis indicated that carbapenems used for more than 10 days within 1 month before sample collection (OR=6.201，95%CI：1.339-28.729， P=0.020) was an independent risk factors for CRO. The severe infection rate within 72 hours of empirical anti-infection treatment was 24.7% (25/101), which of the CRO group (14/25, 56.0%) was higher than the CSO group (11/76, 14.4%). The difference was statistically significant (χ2= 17.417, P=0.000). Five cases died during hospitalization, all of whom were children with CRO. Conclusion: Acute leukemia in children had high severe infection rate caused by CRO infections. Carbapenem exposure for more than 10 days within one month prior to infections was an independent risk factor.

Key words: Children, Acute leukemia, Carbapenem-resistant organism