Impact of individualized active surveillance of carbapenem-resistant enterobacteriaceae on the infection rate in intensive care units: a 3-year retrospective study in a teaching hospital of People's Republic of China Shu Li,1 Fu-Zheng Guo,2 Xiu-Juan Zhao,1 Qi Wang,3 Hui Wang,3 You-Zhong An,1 Feng-Xue Zhu1,21Department of Critical Care Medicine, Peking University People’s Hospital, Beijing, People’s Republic of China; 2Trauma Centre, Peking University People’s Hospital, Beijing, People’s Republic of China; 3Department of Clinical Laboratory, Peking University People’s Hospital, Beijing, People’s Republic of ChinaPurpose: Active surveillance of carbapenem-resistant Enterobacteriaceae (CRE) may contribute to the decline of the infection rate. Individualized active surveillance of CRE could cost less than screening all patients. However, the impact of individualized active surveillance on the CRE infection rate in intensive care units (ICUs) has not been well described.Patients and methods: We retrospectively studied the clinical data of all patients admitted in the ICUs of a tertiary-care hospital in China from 2015 to 2017 during two periods, before and after the implementation of individualized active surveillance. During period 1 (January 2015–April 2016), no screening protocol was used. During period 2 (May 2016–December 2017), we implemented active CRE screening for selected patients according to their clinical characteristics. The trend of CRE rate infection was analyzed by a joinpoint regression model, and multivariate analysis was performed to analyze the association of active surveillance, Acute Physiology and Chronic Health Evaluation (APACHE) II score, prior antimicrobial use, length of mechanical ventilation (MV) before infection, and other risk factors with CRE infection rate.Results: A total of 5,372 patients were included. After assessing the patients’ clinical characteristics, 72.3% (3,882/5,372) were considered to be at high risk of CRE infection. During period 1, the infection percent of CRE increased by 13.04% every month (95% CI: 5.2–21.5). During period 2, the infection rate decreased (monthly percent change, −3.57%; 95% CI −6.9 to −0.1, P