Microbial colonies isolated on surgical sites and surgical instruments intraoperatively at a public referral hospital, Kenya

Abstract

Background: The surgical field is considered to remain aseptic during operations. This may change with time as surgery progress, microbes eventually settle in the surgical field and cause contamination of sterilized surgical instruments and surgical sites. Microbial contamination of surgical sites and instruments leads to the development of Surgical Site Infection (CDC, 2019).

Researchers have demonstrated intraoperative contamination of surgical instruments and surgical sites was common in spite of various means of preventing Surgical Site Infections, such as skin preparation preoperatively, prophylactic antibiotics, and intraoperative aseptic technique. Different types of microorganisms have been isolated on surgical instruments mainly postoperatively (Saito et al, 2014). This study dwelled on the intraoperative sessions of surgery. Change of surgical instruments and drapes after prolonged exposure is recommended strongly as basic practice.

Materials and Methods: Analytical cross-sectional design was used. The study subjects were 93 surgical patients pre and post-surgery wound swabs were done. Instruments swabs was done at intervals from 0 minute then hourly up to 4 hours. Check lists and laboratory forms were used for data collection. Sample size was 651 (93x7) 2 samples on the surgical site and 5 samples from the instruments. SPSS was used to analyze descriptive statistics.

Results: Staphylococcus species had the highest frequency and percentage both on the surgical site pre and post-surgery as well as instrument swabs at all levels of time from time 0 then hourly up to 4 hours. The staphylococcus species infection range was 7% to 20%. Others included Bacillus species, klebsiella and Escherichia coli at minimal percentages.

Conclusion: In surgical site infections, the study demonstrates that the frequently occurring organism is Staphylococcus aureus. This is due to normal flora of skin of patients and also shed by the personnel in the theatres. There was evidence of microbial colonization on the surgical sites and instruments.

Recommendation: Change of surgical instruments and drapes, enhanced surgical prepping and enhance instrument processing and sterilization.