[Surveillance of surgical wound infections. 18-month experience in the Instituto Nacional de Cancerología].

OBJECTIVE: To calculate the surgical site infection (SSI) rates with a surgical prospective surveillance program and postdischarge follow-up. MATERIAL AND METHODS: During a 18 months period (01/01/93 to 04/30/94), a surgical wound surveillance program followed on the surgeries practiced at the National Institute of Cancerology, a referral center situated in Mexico City. Rates per 100 surgeries were calculated for the surgical services and for each of the wound class strata. The SS's were classified according to the 1992 Center for Disease Control definitions for surgical infections. RESULTS: Three thousand, three hundred and severity-two surgeries were assessed; 313 were diagnosed as infected: 140 (44.7%) were superficial incisional, 137 (43.7%) were deep incisional and 36 (11.5%) were organ and space infections. The SSI rate for this period was 9.28%; for the clean, clean-contaminated, contaminated and dirty surgeries the rates were 7.35, 10.5, 17.3 and 21.5% respectively. The rates for each service were: gastroenterology, 14.13%; breast tumors, 11.08%; mixed tumors, 10.98%; gynecology, 9.06%; urology, 7.38%; head and neck, 7.13%, and thoracic surgery, 1.81%. On average SSI were detected at 11.6 +/- 6.23 days, eighty-five (27.16%) were diagnosed while the patient was in-hospital, the remaining 228 (72.84%) were detected after discharge. In 134 (42.8%) patients a culture was obtained. The bacteria most frequently found were: E. coli, 38 (22.5%); coagulase negative Staphylococci, 23 (13.6%); Pseudomonas sp., 22 (13%); S. aureus, 16 (9.4%); and Enterococcus, 13 (7.7%). CONCLUSIONS: The prospective surveillance program with a follow-up for 30 days increased by 400% the chance to identify a SSI. The SSI rate for clean and clean-contaminated surgeries are above the rates reported in the literature.