Nasal colonization of methicillin resistant Staphylococcus aureus (MRSA) does not predict subsequent infection in the intensive care unit

Hospital acquired infections with Staphylococcus aureus; especially methicillin resistant S. aureus (MRSA) is a major cause of morbidity and mortality in the United States. The aim of this study was compare the rates of MRSA infections between MRSA colonized and not-colonized patients. A retrospective, electronic and paper chart review of all adult patients admitted to the intensive care unit (ICU) from 2007 to 2010 was screened for MRSA. Endpoints were pyogenic pneumonia, sepsis, endocarditis, skin and soft tissue infections, osteomyelitis and septic arthritis. Patients who were not screened for MRSA were excluded from the study. A total of 1203 patients were admitted and screened for MRSA colonization on admission to the ICU from 2007 to 2010. Two main groups were made for between colonized and not-colonized based on MRSA screening. Fifty-seven (57) positive colonized and 122 not-colonized patients' charts were randomly selected. The mean age of the study population was 61.7 ± 18.4 (range, 19-94); there were 80 (44.69%) males and 99 (55.31%) females. The occurrence of infection with MRSA with either lower respiratory tract infection or blood stream infection identified on the time of ICU admission was similar for patients with and without MRSA nasal colonization 3.51% vs. 2.46%; p = 0.459. There was no observed difference in the rates of MRSA infection between those who tested colonized and not-colonized.