Surgical site infection at a tertiary academic hospital in Johannesburg: a one year audit

Abstract

Introduction: Surgical site infection (SSI) occurs during the first 30 days after surgery and affects either the incision or deep tissue at the site of operation. Surgical site infection accounts for approximately 38% of hospital-acquired infections globally and is associated with increased length of hospitalization and mortality, and therefore increased cost of health care. The type of causative organisms in SSI is influenced by among others the type of surgery. Frequently isolated organisms in SSI include Escherichia coli, coagulase-negative Staphylococci, Enterococcus species and Staphylococcus aureus.

Aim: The aim of this study was to determine the incidence of SSI, causative organisms and factors which were associated with its occurrence at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH).

Methods: This was a retrospective review of records of patients who were operated over the 12 months and subsequently developed SSI. Data of patients who developed SSI were extracted from records of weekly morbidity and mortality meetings of the Department of Surgery, which are captured on the Research Electronic Data Capture (REDCap). Data retrieved included demographic information, co-morbidities, nature of surgery, class of SSI and microscopy, culture and sensitivity results and overall outcome including the length of hospital stay. Descriptive, bivariate and multivariate analysis of the data was performed.

Results: During the study period 3005 surgical procedures were performed of which 46.8% were elective operations. A total of 147 records of patients who developed SSI were found. The incidence of reported SSI was 4.8% (147/3005) with 72.6% (93/147) occurring in males. The mean age of all the patients who developed SSI was 47.3 ± 17.21 years (range: 16-82 years). E. coli and P. aeruginosa from 44% (36/82) and 29.3% (24/82), respectively. Of patients who developed SSI, 30.5% (39/128) had diabetes mellitus, 21.9% (28/128) had hypertension and 18.8% (24/128) had both diabetes and hypertension while 15.6% (20) of the patients were known to be HIV positive.

Conclusion: The overall rate of SSI in the surgical patients was 4.8%. Majority of SSI occurred males. The two most commonly cultured organisms in patients who developed SSI were E. coli and P. aeruginosa. Thirty-one percent of the patient who were diagnosed with SSIs had diabetes mellitus.