688. The effect of cefazolin-based antimicrobial prophylaxis protocol on the isolation of bacteria from a surgical wound after clean orthopaedic surgery
Session: Poster Abstract Session: Skin, Soft Tissue and Joint Infections
Friday, October 21, 2011
Room: Poster Hall B1
Background: Since the major pathogen of orthopedic surgical site infection (SSI) is staphylococci, cefazolin is the recommended prophylactic antibiotic in clean orthopedic surgeries. However, the evidence of cefazolin-based antimicrobial prophylaxis on the prevention of SSI after that has rarely been reported. The aim of this study is to evaluate the effect of cefazolin-based prophylaxis on the isolation rate of bacteria from surgical wounds of suspected SSI patients.

Methods: At our department, methicillin-resistant S. aureus (MRSA) active surveillance and decolonization for preoperative patients has been performed since 2004, and the cefazolin-based prophylaxis protocol for 2 days in clean orthopedic surgery has been implemented since 2008. Data of antimicrobial use, alcohol antiseptic agent use, and bacterial isolation from wounds of patients with suspected SSI who undergo clean orthopedic surgery were collected from July 2004 through December 2010 and analyzed every 6 months.

Results: In all, 302 strains were isolated from 143 cases of suspected SSI. The incidences of each species were as follows: methicillin-sensitive S. epidermidis, 19.5%; MRSA, 17.5%; methicillin-resistant S. epidermidis, 11.3%; methicillin-sensitive S. aureus, 7.6%; and Pseudomonas. aeruginosa, 5.3%. The cefazolin antimicrobial use density (AUD) after January 2008 (78.3 ± 12.8) was significantly higher than that before 2008 (23.0 ± 18.2, p = 0.0027). There was a negative correlation between the cefazolin AUD and the isolation rate of methicillin-sensitive staphylococci (p = 0.0001). A negative correlation was also observed between the cefazolin AUD and the isolation rate of methicillin-resistant staphylococci p = 0.019), especially MRSA (p = 0.0079). There were no correlations between cefazolin AUD and the isolation rate of P. aeruginosa (p = 0.4681) and that between alcohol antiseptic agent use and the isolation rate of MRSA (p = 0.290).

Conclusion: This study suggests that cefazolin-based antimicrobial prophylaxis decreases the incidence of SSI due to methicillin-sensitive staphylococci after clean orthopedic surgery. This prophylaxis may also be useful for the prevention of SSI due to methicillin-resistant staphylococci after that for unknown reasons.

Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Hideki Kawamura, Kazuaki Matsumoto, Toyoyasu Koriyama, Akari Shigemi, Hiroaki Miyanohara, Michiyo Orita, Koichi Tokuda, MD, PhD, MPH, Naoya Kawabata, Setsuro Komiya and Junichiro Nishi, Kagoshima University Hospital, Kagoshima-city, Japan


H. Kawamura, None

K. Matsumoto, None

T. Koriyama, None

A. Shigemi, None

H. Miyanohara, None

M. Orita, None

K. Tokuda, None

N. Kawabata, None

S. Komiya, None

J. Nishi, None

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