Abstract:OBJECTIVE: To study the risk factors for infection with extended-spectrum beta-lactamase (ESBL) producing strains in children. METHODS: The clinical data of 242 pediatric in-patients with lower respiratory tract infections from February 2009 to January 2011 were retrospectively analyzed. The risk factors of ESBL-producing strain infections were investigated using univariate analysis and multivariate logistic regression analysis. RESULTS: Univariate analysis showed that six factors were related with ESBL-producing strain infections: repeated sucking of phlegm (OR: 2.279, P<0.01), tracheal intubation(OR: 3.101, P<0.01), administration of the third generation cephalosporin for more than three days (OR: 3.628, P<0.01), admission to the pediatric intensive care unit (PICU) (OR: 2.378, P<0.01), indwelling of nasogastric tube (OR: 2.460, P<0.01), prophylactic use of antibiotics (OR: 1.747, P<0.05). Multivariate logistic regression showed that the application of the third-generation cephalosporin for more than three days (OR: 5.672, P<0.01), repeated sucking of phlegm (OR: 3.917, P<0.01), tracheal intubation (OR: 3.717, P<0.01), indwelling of nasogastric tube (OR: 2.961, P<0.01), and admission to PICU (OR: 3.237, P<0.01)were the independent risk factors for the infections. CONCLUSIONS: The infections of ESBL-producing strains are caused by many factors, among which the application of the thirdgeneration cephalosporin for more than three days, invasive operations, and admission to PICU are the independent risk factors.