Superficial incisional
Involves only the skin and tissue just beneath it, along the line of the cut. Presents with redness, warmth, swelling, pain or discharge at the wound.
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Disease Focus · Surgical Infections
Surgical site infections · Detection & diagnosis guide
Surgical site infections, understood.
A surgical site infection is an infection that develops in a wound or the tissue around it after surgery. This guide explains the different infections that fall under the SSI umbrella across the surgical sub-specialities, how Australia currently detects and diagnoses them, and how newer diagnostics are speeding that process up.
Setting
Hospital & post-surgical care
Standard
NSQHS Standards · ACSQHC
Key test
Wound swab · culture
3types
superficial, deep, organ-space30days
standard monitoring window after surgery2tests
swab culture and blood markers1standard
national surveillance via ACSQHCWhy this guide exists
Infections after surgery are usually treatable, but only when they are caught early. Knowing what to watch for changes outcomes.
Tricorian Life
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The Science
What is happening
An infection in the wake of surgery.
Surgery creates a wound, and wounds are an entry point for bacteria. Most surgical wounds heal cleanly. When bacteria establish themselves in the wound, the surrounding tissue, or the deeper space operated on, the result is a surgical site infection.
Deep incisional
Reaches the deeper soft tissue layers such as muscle and fascia. Often needs wound opening, drainage, and sometimes a return to theatre.
Organ or space
Involves the organ operated on or the space around it, for example an infected joint after joint surgery or an abscess in the abdomen after bowel surgery. The most serious form.
Who is at higher risk
Longer operations, emergency surgery, diabetes, smoking, obesity, a weakened immune system, and certain procedures carry higher risk. Hospitals actively manage these factors before, during and after surgery.
The usual suspects
The bacteria involved vary by surgery site. Staphylococcus aureus is the most common cause overall, while bowel surgery more often involves bacteria from the gut. The laboratory identifies the exact organism from a sample.
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The Group of Infections
Across the sub-specialities
One family of infections, many different faces.
SSIs take different names and forms depending on the surgery performed. Understanding the group helps you recognise the warning signs relevant to your own operation.
Prosthetic joint & bone infection
After joint replacement or fracture surgery, infection can settle in the joint or bone. Causes pain, swelling and wound problems, and may threaten the implant if deep.
Sternal wound infection
Infection of the breastbone wound after heart surgery. Ranges from a superficial wound problem to deep mediastinitis, a serious infection of the chest cavity.
Anastomotic leak & pelvic abscess
Where the bowel is rejoined, a leak can seed infection in the pelvis, presenting as fever, pain and unwellness in the days after surgery.
Post-caesarean wound infection
Infection of the caesarean incision, and relatedly endometritis, an infection of the womb lining after delivery. Both respond well to early treatment.
Shunt & cranial infection
After brain or spinal surgery, infection may involve the wound, the membranes around the brain (meningitis), or an implanted shunt.
Graft infection
Infection of a prosthetic blood vessel graft is rare but serious, presenting with fever, pain and sometimes bleeding. Managed by specialised vascular teams.
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Detection & Diagnosis
The Australian standard
How Australia finds these infections.
Australian hospitals detect and track SSIs through a combination of bedside assessment, laboratory testing, imaging, and national surveillance coordinated by the Australian Commission on Safety and Quality in Health Care (ACSQHC) under the National Safety and Quality Health Service Standards.
Clinical review of the wound
The first line of detection. Your care team checks for redness, swelling, warmth, pain, discharge and opening of the wound, and asks about fever and how you feel.
Role: Raises suspicion. Standard after every operation.
Wound swab with microscopy, culture & sensitivity
A sample is taken from the wound and sent to the pathology laboratory. The lab identifies the exact bacteria and which antibiotics will work against them.
Role: Confirms the organism and guides antibiotics.
Blood tests: FBC & CRP
A full blood count looks for a raised white cell count and CRP measures inflammation. Together they signal how significant an infection is and track your response to treatment.
Role: Severity and monitoring. See the pathology handbook.
Imaging: ultrasound & CT
Used when deep or organ-space infection is suspected, to look for fluid collections or abscesses that may need draining. See our radiology topic for how these scans work.
Role: Locates deep collections before drainage.
Joint fluid & tissue sampling
For suspected joint or deep infections, fluid or tissue is taken under sterile conditions for culture, the most direct way to confirm infection at the site.
Role: Direct confirmation in deep infection.
National surveillance
Hospitals report SSI data under ACSQHC surveillance programs. This standardised tracking is how Australia measures, benchmarks and continuously improves surgical infection rates.
Role: System-wide monitoring and improvement.
Faster detection
New diagnostics.
Traditional culture takes days while bacteria grow in the laboratory. Newer molecular testing, including PCR-based diagnostics, can detect the DNA of infection-causing organisms in hours rather than days. Tricorian Life is developing a PCR diagnostic aimed at faster detection of surgical infections, including antibiotic resistance markers. You can read more on our innovation page.
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Your Pathway
Step by step
From first sign to treated and recovered.
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Recognise
Redness, warmth, swelling, pain, discharge or fever in the days after surgery. If you are home, contact your surgeon or GP promptly.
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Assess
Your care team examines the wound and reviews your temperature and blood markers to judge how deep the infection goes.
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Sample
A swab, fluid or tissue sample goes to pathology for culture to identify the organism and its antibiotic sensitivities.
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Treat
Antibiotics targeted to the organism, plus drainage of any collection, either at the bedside, under imaging guidance, or in theatre.
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Recover
Wound care and follow-up until healing is complete. Deep infections may need weeks of antibiotics with ongoing monitoring.
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Prevention
What reduces risk
Prevention is a team effort.
Australian hospitals follow structured prevention bundles before, during and after surgery. Many of the most effective measures involve you.
Antibiotics at the right timePreventive antibiotics are given before incision for most operations, timed so they peak during surgery.
Skin preparationAntiseptic washing of the surgical site before the operation reduces the bacteria on the skin.
Keeping warmMaintaining normal body temperature during surgery measurably reduces wound infection rates.
Blood sugar controlHigh blood sugar impairs healing and increases infection risk. Diabetes is actively managed around surgery.
Stop smokingSmoking impairs blood flow and healing. Stopping, even a few weeks before surgery, improves outcomes.
Clean wound care at homeFollow your discharge instructions on keeping the wound clean and dry, and know the signs to report early.
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Support
Where to turn
Concerned about a wound? Here is where to go.
Your surgical team first
Your surgeon's rooms and the hospital where you had your operation are the first port of call for any concern about a wound. They know your procedure, your risk profile and your recovery plan, and they can act fastest.
Tricorian Life
If you need guidance on this space, whether understanding a report, asking about a test, or wanting to know how diagnostics are changing, reach out. Our team will help point you in the right direction. We respond within 24 hours.
Reach out to us
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Sources
Where this guide draws from.
- 1Australian Commission on Safety and Quality in Health Care. Surgical Site Infection Surveillance and the National Safety and Quality Health Service Standards. safetyandquality.gov.au
- 2Centers for Disease Control and Prevention. Surgical Site Infection Event (SSI) definitions. National Healthcare Safety Network.
- 3RCPA Manual. Pathology tests for infection: wound swab microscopy, culture and sensitivity. rcpa.edu.au
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Common Questions
Frequently asked
Questions patients ask most often.
How do I know if my wound is infected?
Watch for increasing redness spreading around the wound, warmth, swelling, new or worsening pain, cloudy or smelly discharge, a wound that opens up, or a fever. Any of these warrants a prompt call to your surgeon or GP, especially in the first weeks after surgery.
How long does a wound swab result take?
Initial results can be available within a day or two, but full culture and antibiotic sensitivity typically take several days because the bacteria must grow in the laboratory. Newer molecular tests can detect organisms much faster, which is one reason this area of diagnostics is evolving quickly.
Do I need antibiotics for every surgical wound problem?
No. Some redness and tenderness is a normal part of healing. Your treating team decides whether the signs point to infection, and only then selects antibiotics, ideally matched to the organism from the culture result.
What if the infection keeps coming back?
Recurrent or persistent infection suggests a deeper source, such as a collection that has not fully drained or involvement of implanted material. Your team will re-image, re-sample, and consider further drainage or revision surgery.
Reach out
Questions about detection or diagnostics?
Whether you are recovering from surgery, supporting someone who is, or working in the field and want to understand where diagnostics are heading, our team can help. We respond within 24 hours.
Talk to our team or email [email protected]