Surgical site infection surveillance at the National Cancer Instistute in Mexico.

Objective. To calculate the surgical sire infection (SSI) rates with a surg ical prospective surveillance program and potdischarge follow-up. Material and methods. During a 18 months period (01/01/93 to 04/30/94), a surgical w ound surveillance program followed on the surgeries practiced at the Nation al Institute of Cancerology, a referral center situated in Mexico City Rate s 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 C enter for Disease Control definitions for surgical infections. Results. Thr ee thousand, three hundred and severity-two surgeries were assesed; 313 wer e 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, con taminated and dirty surgeries the rates were 7.35, 10.5, 17.3 and 21.5% res pectively. The rates for each service were: gastroenterology, 14.13%; breas t 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 dete cted at 11.6+/-6.23 days, eigthy-five (27.16%) were diagnosed while the pat ient was in-hospital, the remaining 228 (72.84%) were detected after discha rge. In 134 (42.8%) patients a culture was obtained. The bacteria most freq uently 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 far clean and clean-contaminated surgeries are above the rates reported in the literature.