Epidemiology and associated factors for nosocomial methicillin-resistant Staphylococcus aureus infection in a tertiary-care hospital

Abstract

We analysed nosocomial MRSA cases between January 2004 and December 2006 in a retrospective case-control study in a 250-bed tertiary-care teaching hospital. During the study period, 265 nosocomial Staphylococcus aureus infections were identified in 231 patients. There was a significant increase in methicillin resistance in isolates (MRSA) from these infections with frequencies for 2004 of 39/88 (443%), 2005 (62/80, 775%), and 2006 (75/97, 773%) (P<0001). Multivariate analysis showed that associated factors for nosocomial MRSA infection were prolonged hospitalization (OR 3982, 95% CI 2235-7094, P<0001), mechanical ventilation (OR 3052, 95% CI 1666-5590, P<0001), surgical operation (OR 2032, 95% CI 1102-3748, P=0023), and male sex (OR 2000, 95% CI 1081-3699, P=0027). The determination of associated factors for methicillin resistance in nosocomial S. aureus infections in hospitals will play an important role in efforts to reduce MRSA infection rates. © Cambridge University Press 2009.