Most surgical site infections (SSIs) that occur after elective procedures are presumed to be due to intraoperative contamination of the operating site by the organisms present at the site. However, studies of microbial cultures of surgical wounds obtained at the end of the surgery suggest otherwise. Some infections are due to organisms not present in the operating site. The authors describe the Trojan Horse hypothesis as explanation for the pathogenesis of SSIs. They propose that a pathogen originating from a site remote from the surgical site such as from the intestinal tract, teeth or the gums causes infection of the sterile postoperative wound. This has been demonstrated in animal studies. According to the authors, this hypothesis also offers a possible answer for the beneficial effects of preoperative oral hygiene measures in preventing SSIs.

Adopting enhanced recovery programs in patients undergoing major gastrointestinal surgical procedure such as mechanical bowel preparation, earlier discharge, minimally invasive surgery and avoiding use of opioids may decrease SSIs by nearly half. Preoperative oral antibiotic before colon surgery is a standard of care, but antibiotic resistance in most pathogens causing SSIs is a big concern. Carrying out genomic-based microbial tracking from the built environment (i.e., the operating room and hospital bed), to the patient′s own microbiome, to the hair and skin of the OR staff, to the surgical field and then to the actual surgical wound may reduce postoperative SSI rates to map the migration of the individual micro-organism.

Source: Alverdy  JC, et al. Lancet Infect Dis. 2020 Mar;20(3):e38-e43.