This document defines and discusses surgical site infections (SSIs). It begins with an introduction and definition of SSIs. It then discusses the epidemiology, classifications, diagnostic criteria, and risk factors of SSIs. The classifications include superficial incisional SSI, deep incisional SSI, and organ/space SSI. Risk factors are divided into patient factors like age and comorbidities, local wound factors, and microbial factors like bacteria type. Common organisms that cause SSIs are also mentioned.

1. • Introduction
• Definition + terminologies
• Epidemiology
• Classifications
• Diagnostic citeria
• Risk factors
• Common organisms

2. SURGICAL SITE INFECTION
(SSI)

3. • Surgical site infections are a major problem in surgical practice.
• In 1992, the term surgical site infection was adopted by the CDC to
differentiate it from wound infections.

4. • SSIs are the 3rd most commion nosocomial infections. 14-16%
• Most common nosocomial infection among surgery patients- 38%.

5. WHAT IS A SURGICAL SITE INFECTION
• A surgical site infection is an infection that occurs in the wound created by
an invasive surgical procedure
• SSI is defined as an infection of the superficial or deep skin incision, or of
an organ or space, occuring up to 30days after surgery if no implant was
left behind or witjin 1 year if an implant was left in place
• Surgical site infections can lead to
I. increased morbidity
II. Increased mortality
III. Increased duration of hospital stay
IV. Increased cost

6. Important terminologies
• Colonization- bacteria present in a wound with no sign or symptoms
of systemic inflammation. Usually less that 105cfu/ml.
• Contamination- transient exposure of a wound to bacteria. Varying
concentrations of bacteria possible. Time of exposure usually less
than 6 hours.
• Infection- this involves systemic and local signs of inflammation with
a bacteria count greater than or equal to 105cfu/ml.

7. Epidemiology

8. CLASSIFICATION
INCISIONAL SSI : This is subdivided into superficial incisional SSI and
Deep incisional SSI
ORGAN/SPACE SSI:

9. SUPERFICIAL INCISIONAL SSI
• Infection occurs with 30days after surgical procedure
+
• involves only skin and subcutaneous tissue of the incision
+
• Patient has at least one of the following
a) Purulent drainage from the superficial incision
b) Organism isolated from an aspetically-obtained culture of fluid or tissue
c) Superficial incision that is deliberately opened by a surgeon and is
culture positive or not cultured and patient has atleast on of the
following signs or symptoms; pain, localised swelling, redness, heat
d) Diagnosis of superficial SSI by surgeon or attending physician

10. THE FOLLOWING CONDITIONS ARENOT SSI
• Stitch abscess (minimal inflammation and discharge confined to the
points of the suture penetration)
• Infection of an episiotomy or newborn circumcision site
• Infected burn wound
• Incisional SSI that extends into the fascial and muscle layers

11. DEEP INCISIONAL SSI
• Infection occurs within 30days after the operation if no implant is left in place or within a
year if implant is in place and the operation appears to be related to the operation
+
• Involves deep soft tissues of the incision, e.g, fascial and muscle layers
+
• Patient has atleast 1 of the following:
a) Purulent discharge from deep deep incision
b) Deep incision spontaneously dehisces or opened by surgeon and is culture positive or
not cultured and fever >38oc, localised pain or tenderness
c) Abscess or other evidence of infection found on direct exam, during invasive
procedure, by histopathologic exam or imaging test
d) Diagnosis of deep SSI by surgeon or attending physician.

12. ORGAN SPACE SSI
• Infection occurs within 30days after the operation if no implant is left in place or within 1
year If implant is in place and the infection appears to be related to the operation
+
• Infection involves any part of the body, excluding the skin incision, fascia or muscle layers
that is opened or manipulated during the operative procedure
+
• Patient has atleast 1 of the following
a) Purulent drainage from drain placed into the organ/space
b) Organism isolated from aspetically obtained culture of fluid or tissue in the organ
soace
c) Abscess or other evidence of infectionfound on direct exam, during invasive procedure
or by histopathologic or exam or imaging test
d) Diagnosis of an organ/space infection by surgeon or attending physician

13. FURTHER CLASSIFICATION
• SEVERITY
a) MINOR- discharge without cellulitis or deep tissue destruction
b) MAJOR- Pus discharge with tissue breakdown, partial or total dehiscence
of the deep fascial layers of wound. Systemic illness present.
TIMING
a) EARLY- infection present within 30 days
b) INTERMEDIATE- infection occurs between 1-3 months
c) LATE- infection presents more than 3 months after surgery

14. RISK FACTOR
• Patient factor
• Local factor
• Microbial factor

15. PATIENT FACTOR