一、概论医院获得性感染 (ｎｏｓｏｃｏｍｉａｌｉｎｆｅｃｔｉｏｎ)是当前重要的公共卫生问题之一。根据美国疾病控制中心于 1991年提出的定义 ,医院获得性感染是患者在住院期间获得的感染 ,入院时既不存在 ,也不处于潜伏期[1] 。临床上常常把入院 48ｈ或72ｈ后发生的感染称为 First, the introduction of nosocomial infection (nosocomialinfection) is currently one of the important public health issues. According to the definition provided by the Centers for Disease Control in 1991, hospital-acquired infections are acquired during hospitalization and are neither hospitalized nor in an incubation period [1]. Clinically often admitted to hospital 48h or 72h after the infection is called