据美国疾病预防中心与控制中心(CDC)统计,每年约有9万例患者死于院内感染。我国每年约有5 000万住院患者,其中约500万患者出现医院感染,每例医院感染者因而曾经延长住院时间达8～10 d,多消耗费用2 000～4 000元人民币,每年造成额外医疗消费约100亿元人民币[2]。根据本院2005及2006年的回顾性调查,出院患者分别为15 361例和16 429 According to the Centers for Disease Control and Prevention (CDC) statistics, about 90,000 patients die of nosocomial infections each year. In China, about 50 million inpatients each year, of which about 5 million have nosocomial infections. As a result, each hospital-based nosocomial infection has prolonged the length of stay of hospitalization by 8 to 10 days and cost more than 2,000 to 4,000 yuan each year, resulting in additional medical treatment each year Consumption of about 10 billion yuan [2]. According to our retrospective survey conducted in 2005 and 2006, 15 361 and 16 429 discharged patients, respectively