Blue Ribbon Abstract Award

Abstract

BACKGROUND/OBJECTIVES: Gram-positive organisms, such as Staphylococcus aureus ( S. aureus ) and Coagulase negative staphylococcus (CNS), are the predominating organisms contributing to prosthetic joint infections. A recent cluster of total hip replacement surgical site infections (SSI) occurred at this hospital in 2004. Four of the six deep SSIs were caused by S. aureus . The patients and OR team members underwent nasal cultures to rule out S. aureus colonization. Several of the patients along with one staff member did have positive nasal cultures as well. Pulse field gel electrophoresis (PFGE) typing determined the strains were genetically distinct and therefore not epidemiologically linked. A protocol was developed at this hospital to identify carriers pre-operatively and treat them with intranasal mupirocin. We hypothesized that pre-operative treatment of patients with positive nasal cultures would decrease the post-operative infection rate. METHODS: At the time of pre-admission testing (PAT), every patient undergoing total joint replacement surgery (including shoulder, hip and knee) was nasally cultured. Between December 2004 and December 2005, a total of 435 patients were nasally cultured. All patients who were culture positive for S. aureus were treated with intranasal mupirocin ointment twice a day for seven (7) days. Additionally, patients identified with methicillin resistant staphylococcus aureus (MRSA) were instructed to undergo a chlorhexidine antiseptic soap shower before surgery, and were given vancomycin for their surgical prophylaxis. MRSA patients were also placed in Contact isolation when admitted to the hospital. All non- MRSA patients received cefazolin or clindamycin as the surgical prophylaxis. RESULTS: Preoperative nasal screening cultures determined a S. aureus carrier rate of 27 % or 119 patients out of 435 patients cultured. MRSA accounted for 16.8% (20/119) of the S. aureus isolates. We observed zero (0) deep S. aureus associated SSI and one superficial SSI over a 12 -month period as compared with the historical rate of 1.64% (p CONCLUSIONS: Identifying and treating S. aureus carriers with a full course of mupirocin does impact the rate of total joint S. aureus surgical site infections. These findings impact hospital length of stays, readmissions, post-op complications, hospital and patient costs, and above all improving patient outcomes.