The degree of bacterial contamination remains a major determinant in the development of surgical site infections (SSI), which continue to be a leading cause of morbidity among surgical patients. For this reason, we performed a prospective survey on the relative frequency of surgical site infections based on bacterial contamination categories. Of the 774 operations in our department over a six-month period from January 1 to July 31, 1989, the overall surgical site infection rate was 7.8% with specific surgical site infection rates of 2.5%, 5.8%, 14.7% and 16.9% on clean, clean-contaminated, contaminated and dirty operations respectively. A comparison with published acceptable surgical wound infection rates among the different bacterial contamination categories showed comparable results except for contaminated cases (p = 0.0376). Deep incisional SSI tended to be higher among dirty operations with a risk eight times higher compared with clean operations.

The use of prophylactic antibiotics was also noted as they were practiced by the different surgeons, without specific guidelines as to their use. An in-depth study is needed to determine the effects of antibiotic prophylaxis on surgical site infection rate.