9Weber WP,Zwahlen M,Reck S,et al. Economic burden of sur- gical site infections at a European university hospital [J]. In- fect Control Hosp Epidemiol, 2008,29 (7) : 623-629.
10Klevens RM, Edwards JR, Richards CL JR,et al. Estimating health care -associated infections and deaths in U.S. hospitals [J]. Public Health Rep,2007,122(3) :160-166.