🦠 Infective Endocarditis Diagnosis (Modified Duke)
The modified Duke (and 2023 Duke-ISCVID) criteria classify infective endocarditis as definite, possible, or rejected using major and minor criteria.
Clinical takeaway
A negative transthoracic echo with high clinical suspicion warrants a transesophageal echo before rejecting the diagnosis (original synthesis · not guideline verbatim).
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When to use
Use to combine microbiologic, imaging, and clinical findings into a diagnostic category that guides antibiotics and surgical assessment.
How it works
Definite = 2 major, or 1 major + 3 minor, or 5 minor; possible = 1 major + 1 minor, or 3 minor; otherwise rejected. Major = typical microbiology or imaging evidence; minor = predisposition, fever, vascular/immunologic phenomena, supporting microbiology.
Key points
- A negative transthoracic echo with high clinical suspicion warrants a transesophageal echo before rejecting the diagnosis (original synthesis · not guideline verbatim).
- The 2023 Duke-ISCVID revision adds cardiac CT, intraoperative findings, and PET/CT and broadens predisposition to CIED/TAVR/prior IE.
- Pathologic criteria (organism in vegetation/valve tissue) confirm directly and override the clinical count.
References
- Li JS, et al. Modified Duke criteria. Clin Infect Dis 2000.
- Fowler VG, et al. 2023 Duke-ISCVID criteria. Clin Infect Dis 2023.
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Major · microbiology (2 sets of blood cultures with typical IE organisms / persistently positive / single C. burnetii or IgG antibody > 1:800) | No |
|---|---|
| Major · imaging (echo/cardiac CT showing vegetation/abscess/perivalvular involvement/new prosthetic dehiscence; or surgical/PET evidence) | No |
| Minor · predisposition (underlying heart disease/prosthetic valve/CIED/IV drug use/prior IE) | No |
| Minor · fever ≥ 38℃ | No |
| Minor · vascular phenomena (arterial embolism/septic pulmonary infarction/mycotic aneurysm/intracranial hemorrhage/Janeway lesions) | No |
| Minor · immunologic phenomena (glomerulonephritis/Osler nodes/Roth spots/rheumatoid factor) | No |
| Minor · microbiologic evidence (not meeting a major criterion) | No |
→Duke determinationRejected (needs exclusion/reassessment)
- Count：Major criteria 0, minor criteria 0 → Rejected (needs exclusion/reassessment)
- Decision rule：Definite = 2 major or 1 major + 3 minor or 5 minor; possible = 1 major + 1 minor or 3 minor; otherwise rejected
- Management direction：Assess other causes of fever/bacteremia; reject if a firm alternative diagnosis exists, or resolution with < 4 days of antibiotics, or no evidence at surgery/autopsy
| Major · microbiology (2 sets of blood cultures with typical IE organisms / persistently positive / single C. burnetii or IgG antibody > 1:800) | Met |
|---|---|
| Major · imaging (echo/cardiac CT showing vegetation/abscess/perivalvular involvement/new prosthetic dehiscence; or surgical/PET evidence) | Met |
| Minor · predisposition (underlying heart disease/prosthetic valve/CIED/IV drug use/prior IE) | Met |
| Minor · fever ≥ 38℃ | Met |
| Minor · vascular phenomena (arterial embolism/septic pulmonary infarction/mycotic aneurysm/intracranial hemorrhage/Janeway lesions) | Met |
| Minor · immunologic phenomena (glomerulonephritis/Osler nodes/Roth spots/rheumatoid factor) | Met |
| Minor · microbiologic evidence (not meeting a major criterion) | Met |
→Duke determinationDefinite IE (clinical criteria)
- Count：Major criteria 2, minor criteria 5 → Definite IE (clinical criteria)
- Decision rule：Definite = 2 major or 1 major + 3 minor or 5 minor; possible = 1 major + 1 minor or 3 minor; otherwise rejected
- Management direction：Start targeted antibiotics per guidelines (based on blood culture and susceptibility), assess surgical indications (heart failure/uncontrolled infection/high embolic risk/perivalvular abscess), manage with a multidisciplinary IE team
Frequently asked questions
- What is Infective Endocarditis Diagnosis (Modified Duke)?
- The modified Duke (and 2023 Duke-ISCVID) criteria classify infective endocarditis as definite, possible, or rejected using major and minor criteria.
- How is Infective Endocarditis Diagnosis (Modified Duke) calculated? What is the core formula?
- Definite = 2 major, or 1 major + 3 minor, or 5 minor; possible = 1 major + 1 minor, or 3 minor; otherwise rejected. Major = typical microbiology or imaging evidence; minor = predisposition, fever, vascular/immunologic phenomena, supporting microbiology.
- When is Infective Endocarditis Diagnosis (Modified Duke) used?
- Use to combine microbiologic, imaging, and clinical findings into a diagnostic category that guides antibiotics and surgical assessment.
- What are the key clinical points for Infective Endocarditis Diagnosis (Modified Duke)?
- A negative transthoracic echo with high clinical suspicion warrants a transesophageal echo before rejecting the diagnosis (original synthesis · not guideline verbatim). The 2023 Duke-ISCVID revision adds cardiac CT, intraoperative findings, and PET/CT and broadens predisposition to CIED/TAVR/prior IE. Pathologic criteria (organism in vegetation/valve tissue) confirm directly and override the clinical count.
- What are the limits and cautions when using Infective Endocarditis Diagnosis (Modified Duke)?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- How is Infective Endocarditis Diagnosis (Modified Duke) calculated in practice? Can you show a worked example?
- Inputs: Major · microbiology (2 sets of blood cultures with typical IE organisms / persistently positive / single C. burnetii or IgG antibody > 1:800) No, Major · imaging (echo/cardiac CT showing vegetation/abscess/perivalvular involvement/new prosthetic dehiscence; or surgical/PET evidence) No, Minor · predisposition (underlying heart disease/prosthetic valve/CIED/IV drug use/prior IE) No, Minor · fever ≥ 38℃ No, Minor · vascular phenomena (arterial embolism/septic pulmonary infarction/mycotic aneurysm/intracranial hemorrhage/Janeway lesions) No, Minor · immunologic phenomena (glomerulonephritis/Osler nodes/Roth spots/rheumatoid factor) No, Minor · microbiologic evidence (not meeting a major criterion) No → Result: Duke determination Rejected (needs exclusion/reassessment)（Count: Major criteria 0, minor criteria 0 → Rejected (needs exclusion/reassessment), Decision rule: Definite = 2 major or 1 major + 3 minor or 5 minor; possible = 1 major + 1 minor or 3 minor; otherwise rejected, Management direction: Assess other causes of fever/bacteremia; reject if a firm alternative diagnosis exists, or resolution with < 4 days of antibiotics, or no evidence at surgery/autopsy） Inputs: Major · microbiology (2 sets of blood cultures with typical IE organisms / persistently positive / single C. burnetii or IgG antibody > 1:800) Met, Major · imaging (echo/cardiac CT showing vegetation/abscess/perivalvular involvement/new prosthetic dehiscence; or surgical/PET evidence) Met, Minor · predisposition (underlying heart disease/prosthetic valve/CIED/IV drug use/prior IE) Met, Minor · fever ≥ 38℃ Met, Minor · vascular phenomena (arterial embolism/septic pulmonary infarction/mycotic aneurysm/intracranial hemorrhage/Janeway lesions) Met, Minor · immunologic phenomena (glomerulonephritis/Osler nodes/Roth spots/rheumatoid factor) Met, Minor · microbiologic evidence (not meeting a major criterion) Met → Result: Duke determination Definite IE (clinical criteria)（Count: Major criteria 2, minor criteria 5 → Definite IE (clinical criteria), Decision rule: Definite = 2 major or 1 major + 3 minor or 5 minor; possible = 1 major + 1 minor or 3 minor; otherwise rejected, Management direction: Start targeted antibiotics per guidelines (based on blood culture and susceptibility), assess surgical indications (heart failure/uncontrolled infection/high embolic risk/perivalvular abscess), manage with a multidisciplinary IE team）