Purpose: Asymptomatic colonization with methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-sensitive Staph. aureus (MSSA) has been described as a risk factor for subsequent surgical site infection. Colonization of nares, either present at admission to the hospital or acquired during hospitalization, increases the risk for infection. Identifying Staph. aureus colonization in the presurgical screening process is important in reducing subsequent surgical site infection. We performed anterior nares surveillance screens of 6551 inpatient surgeries using polymerase chain reaction (PCR) assay. This rapid technology provided results in less than 24 hrs and a decolonization protocol was administered.

Method: Patients admitted for orthopedic surgery were screened in the prescreening unit. The treatment intervention for MRSA and MSSA patients was 5-day application of intranasal mupirocin 2% applied twice daily. In addition, MRSA positive patients were instructed to bathe with chlorhexidine 2% for 5 days and were rescreened prior to surgery. Contact precautions were implemented if the second screen was positive for MRSA. All MRSA positives received vancomycin for surgical prophylaxis.

Results: From July 17, 2006 through August 31, 2007, 6551 patients were screened; 1471 (22%) were MSSA positive and 291 (4%) were MRSA positive. Repeat nasal screens were obtained from MRSA patients prior to surgery and revealed 86% eradication. In the cohort of positive screens, there were 3 MSSA infections (0.2%) and 3 MRSA infections (1.0%). In the 4789 negative screens there were 7 infections (1 MRSA and 6 MSSA). The surgical site infection rate in the screened patients was 0.2%. In an equivalent group of unscreened patients from the prior year, the infection rate had been 0.4%.

Conclusion: We have successfully implemented an MRSA and MSSA eradication program for all inpatient surgeries during the prescreening process. It has allowed for early identification of patients colonized with MRSA and MSSA, decolonization treatment, and appropriate surgical prophylaxis for MRSA. Since implementation we have documented a significant reduction in infection rates due to MRSA and MSSA. A multidisciplinary approach with strong administrative support and consistent communication was vital to the implementation of the program.