Influences of Type and Duration of Antimicrobial Prophylaxis on an Outbreak of Methicillin-Resistant Staphylococcus aureus and on the Incidence of Wound Infection

OBJECTIVE: To clarify how antibiotic prophylaxis influenced an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) and postoperative infection. DESIGN: Retrospective review. SETTING: University-affiliated teaching hospital. PATIENTS: All patients (n=1824) undergoing subtotal esophagectomy, gastrectomy, or colorectal surgery during the period 1982 through 1995. MAIN OUTCOME MEASURES: Type, timing, and duration of prophylactic antibiotics. Postoperative infection by the Centers for Disease Control and Prevention definition and the organisms isolated. RESULTS: Third-generation cephalosporins were frequently administered for prophylaxis during the period 1982 through 1990. The rate of isolates of MRSA from the infected site increased, peaking in 1988 to 1990. Since 1991 to 1992, along with a marked decrease in third-generation cephalosporin use, the rates of MRSA isolated have declined dramatically. The timing of administration changed from postoperative to intraoperative. Although the duration was gradually decreased, coverage was still provided until about the fifth postoperative day, even during 1993 to 1995. Prolonged coverage did not reduce the rate of superficial incisional or organ/space surgical site infection or that of pneumonia. CONCLUSIONS: Overuse of third-generation cephalosporins for long periods caused an MRSA outbreak. Long-term prophylaxis did not lower infection rates. The briefest possible prophylaxis with first- or second-generation cephalosporins should be used in general surgery.