Surgical site infection

Updated May 21, 2025

Background

Overview

Definition

SSI is an infection that develops within 30 days after surgery, or within one year if an implant is involved, impacting either the incision or the deeper tissues at the surgical site.

Pathophysiology

SSIs result from the contamination of the surgical site with microorganisms, which can occur during the procedure or postoperatively. The pathogens responsible vary by surgery type, with the most commonly isolated organisms including S. aureus, coagulase-negative staphylococci, Enterococcus species, and E. coli.

Epidemiology

SSIs are estimated to occur in 2-4% of inpatient surgical procedures in the US, accounting for 20-31% of all hospital-acquired infections.

Risk factors

Numerous patient-related and procedure-related factors influence the risk of SSI. These include longer hospital stay, obesity, diabetes, hypertension, coronary artery disease, congestive HF, COPD, neurologic diseases, tobacco use, alcohol use, depression, dementia, anemia, immunosuppressive agents, HIV/AIDS, hypoalbuminemia, and postoperative hyperglycemia.

Disease course

SSI typically present with signs of inflammation such as localized redness, warmth, swelling, and pain at the incision site. Fever and purulent discharge may also be present. In severe cases, SSI can lead to wound dehiscence or abscess formation.

Prognosis and risk of recurrence

SSI can lead to significant morbidity, prolonged hospital stays, increased healthcare costs, and in severe cases, can be life-threatening. SSIs are associated with a 2-11-fold increase in mortality risk. The prognosis can be improved with early detection, appropriate management, and adherence to preventive measures.

Guidelines

Key sources

The following summarized guidelines for the evaluation and management of surgical site infection are prepared by our editorial team based on guidelines from the American Society of Colon and Rectal Surgeons (ASCRS 2024), the European Committee on Infection Control (EUCIC/ESCMID 2024), the American Academy of Orthopaedic Surgeons (AAOS 2023,2018), the World Society of Emergency Surgery (WSES 2020), the Asia Pacific ...

Screening and diagnosis

Surveillance for SSIs

As per APSIC 2019 guidelines:

Obtain surveillance of SSIs using accepted international methodology.

Hospitals should evaluate their SSI, S. aureus, MRSA, and mupirocin resistant rates, if available, to determine whether implementation of a screening program is appropriate.

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Medical management

Antibiotic therapy, indications: as per IDSA 2014 guidelines, consider administering systemic antimicrobial therapy in conjunction with incision and drainage in patients with SSIs associated with a significant systemic response, such as:

erythema and induration extending > 5 cm from the wound edge

fever > 38.5 °C

HR > 110 bpm

WBC > 12,000 cells/mcL.

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Surgical interventions

Suture removal and wound drainage: as per IDSA 2014 guidelines, perform suture removal plus incision and drainage in patients with SSI.

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Specific circumstances

Patients undergoing colorectal surgery, general principles

As per ASCRS 2024 guidelines:

Consider implementing a SSI bundle for patients undergoing colorectal surgery to reduce the incidence of SSI.

Consider performing minimally invasive colorectal surgery to reduce the incidence of SSI.

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Preventative measures

Preoperative bathing: as per APSIC 2019 guidelines, advise patients undergoing surgery to have at least 1 bath with antimicrobial or non-antimicrobial soap before surgery.

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