Surgical wound infection surveillance in general surgery procedures at a teaching hospital in Pakistan

A surveillance system was established at the Aga Khan University Hospital in Karachi, Pakistan, to determine surgical wound infection (SWI) rates, trends, and risk factors; and to compare rates with those reported by the National Nosocomial Infection Surveillance (NNIS) system of the Centers for Disease Control and Prevention.

Surveillance was performed from January 1997 to December 1999. Risk categorization was on the basis of the NNIS system. P <.05 was set for statistically significant difference between groups. Data were analyzed using the Epi-Info software (version 6.04, CDC, Atlanta, Ga).

Overall SWI rates for the NNIS risk categories 0, 1, 2, and 3 were 1.9%, 3.7%, 6.7%, and 5.1%, respectively. SWI rate in 0 risk category decreased from 3% in 1997 to 1.1% in 1999 (P =.06). Multivariate analysis showed that SWI rates were higher after mastectomy (odds ratio [OR] 4.28, 95% confidence interval [CI] 1.8-10), hernia repair (OR 3.28, 95% CI 1.6-6.7), gastrointestinal resection (OR 2.2, 95% CI 0.88-5.9), skin procedures (OR 1.97, 95% CI 0.89-4.3), appendectomy OR 0.57, 95% CI 0.20-1.60, and miscellaneous procedures (OR 3.6, 95% CI 1.6-7.7), as compared with cholecystectomy. Other risk factors were contaminated type of operation (OR 2.6, 95% CI 1.2-5.5), and duration of operation exceeding the NNIS standard of "T" hours (OR 2.6, 95% CI 1.7-4).

The SWI rates at the Aga Khan University Hospital are higher than the NNIS standards. There was a downward trend in the SWI rates during the surveillance period. A decrease in the duration of surgical procedures could further reduce the risk.