Clinical study on postoperative infections caused by methicillin-resistant Staphylococcus aureus after gastrointestinal surgery

Abstract

We studied 308 postoperative infections (216 patients) after gastrointestinal surgery during 1987-1991, to elucidate the incidence of postoperative infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and its correlation to clinical background factors. Results were as follows: (1) MRSAs were isolated from 25.9% out of 216 patients or 22.4% out of 308 infections. (2) The isolation rate of MRSA was significantly high in infectious enterocolitis (64.7%, p < 0.001), intraabdominal infections (52.5%, p < 0.001) and respiratory tract infections (35.3%, p < 0.05). On the other hand, it was significantly low in bacteremias (9.28%, p < 0.001), wound infections (13.6%, p < 0.05) and urinary tract infections (3.33%, p < 0.05). (3) MRSAs were found more frequently in male (p < 0.05), younger patients (p < 0.05) and patients with malignant disease (p < 0.10). Whereas no difference was recognized between patients with or without complication. (4) The isolation rate of MRSA by the kind of antibiotics used after surgery, was 0% (0/20, the 1st generation cephems), 17.2% (10/58, the 2nd generation cephems) and 54.5% (48/88, the 3rd generation cephems). Significant differences were found among each group (p < 0.05, p < 0.001). (5) During 1990-1991 when the 1st generation cephems were used frequently, MRSAs were found significantly lower in frequency than during 1987-1989 (p < 0.05). Especially a marked decrease in the rate of MRSA (51.4% to 8.33%, p < 0.05) was seen among patients after upper gastrointestinal surgery.(ABSTRACT TRUNCATED AT 250 WORDS)