A surveillance program for surgical wound infections at the National Institute of Cancerology of Mexico

OBJECTIVES: To evaluate the results of a prospective wound infection surveillance program during its first semester of operation, and to analyse the risk factors associated to wound infection. METHODS AND DESIGN: From January 01 to June 30 1993, 1103 surgeries were prospectively followed. The incidence rates of infection were calculated and a case control analysis was done to evaluate the associated risk factors to POWI (postoperative wound infection). SETTING: An oncological tertiary-care center. RESULTS: The POWI rate was 9.0 per 100 surgeries. By univariate analysis the associated risk factors were: obesity (OR = 2.07 CI95% = 1.19-3.64), one drainage (OR = 2.10 CI = 1.33-3.31), two drainages (OR = 3.14 CI = 1.85-5.26), length of stay of the drainage (patients with wound infection: 15.2 +/- 6.7 days vs. patients without wound infection: 8.2 +/- 6.6 days), duration of operation (patients with wound infection: 188 +/- 163 minutes vs. patients without wound infection: 122 +/- 127 minutes) and duration of preoperative hospitalization (patients with wound infection: 2.9 +/- 6.4 days vs. patients without wound infection 1.5 +/- 3.0 days). The associated risk factors by regression analysis were: obesity (OR = 1.93 CI = 1.08-3.43), two drainages (OR = 2.09 CI = 1.03-4.05) duration of operation > = 120 minutes (OR = 1.96 CI = 1.00-3.86) and duration of preoperative hospitalization (OR = 1.03 CI = 1.00-1.09). CONCLUSIONS: The program showed a previous under-reporting of POWI from 4.2-4.8 per 100 surgeries in the previous seven years to 9.0 in the first semester of operation. It also identified the associated risk factors to POWI in our institution.