Skip to main content

Table 1 Health protection agency definition of superficial and deep surgical site infection

From: The effect of high dose antibiotic impregnated cement on rate of surgical site infection after hip hemiarthroplasty for fractured neck of femur: a protocol for a double-blind quasi randomised controlled trial

Superficial incisional infection

Deep incisional infection

SSI that occurs within 30 days of surgery, involves only the skin or subcutaneous tissue of the incision & meets at least one of the following criteria:

SSI involving the deep tissues (i.e. fascial & muscle layers), within 30 days of surgery (or 1 year if an implant is in place) and the infection appears to be related to the surgical procedure & meets at least one of the following criteria:

1. Purulent drainage from superficial incision

1. Purulent drainage from deep incision (not organ space)

2. Culture of organisms and pus cells present:

2. Organisms from culture and pus cells present in:

fluid / tissue from superficial incision wound swab from superficial incision

Fluid / tissue from deep incision or wound swab from deep incision

3. At least 2 symptoms of inflammation:

3. Deep incision dehisces or deliberately opened and patient has at least 1 symptom of:

Pain, tenderness, localised swelling, redness, heat and either:

1) Incision deliberately opened to manage infection

Fever or localised pain/tenderness


4. Abscess or other evidence of infection in deep incision:

Re-operation / histopathology / radiology

2) Clinicians diagnosis of superficial SSI

5. Clinicians diagnosis of deep incisional SSI

Note: Stitch abscesses (minimal inflammation/discharge at suture point) do not classify as SSI

Note: An infection involving both superficial and deep incisional = deep incisional inflammation/discharge at suture point) do not classify as SSI