Duke Endocarditis Criteria
Select major and minor Duke criteria to classify infective endocarditis as Definite, Possible, or Rejected.
Use the Duke Endocarditis Criteria
Duke Criteria
Major Criteria
Major 1 — Positive Blood Cultures
Typical organisms in ≥2 cultures, persistently positive cultures, or single positive for Coxiella burnetii / anti-phase 1 IgG >1:800
Major 2 — Evidence of Endocardial Involvement
Echo: oscillating mass, abscess, or new prosthetic valve dehiscence; new valvular regurgitation; or positive 18F-FDG PET/CT (prosthetic valve >3 months, per 2023 Duke-ISCVID update)
Minor Criteria
Minor 1 — Predisposing Condition
Predisposing heart condition (valvular disease, congenital HD, prior IE, prosthetic valve) or intravenous drug use
Minor 2 — Fever
Temperature ≥38.0 °C (100.4 °F)
Minor 3 — Vascular Phenomena
Major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhage, or Janeway lesions
Minor 4 — Immunologic Phenomena
Glomerulonephritis, Osler nodes, Roth spots, or positive rheumatoid factor
Minor 5 — Microbiologic Evidence
Positive blood culture not meeting a major criterion, or serologic evidence of active infection with organism consistent with IE
Classification Result
Classification Rules
- Definite: 2 major; or 1 major + 3 minor; or 5 minor
- Possible: 1 major + 1 minor; or 3 minor
- Rejected: firm alternative diagnosis, resolution ≤4 days antibiotics, or criteria not met
Summary
The modified Duke criteria are the standard clinical framework for diagnosing infective endocarditis (IE). Originally published in 1994 and revised in 2000 (with imaging criteria incorporating the 2023 Duke-ISCVID 18F-FDG PET/CT update for prosthetic valves), they divide findings into two major criteria (positive blood cultures and echocardiographic or PET/CT evidence) and five minor criteria (predisposing conditions, fever, vascular phenomena, immunologic phenomena, and microbiologic evidence). A case is classified as Definite IE with 2 major, 1 major + 3 minor, or 5 minor criteria; Possible IE with 1 major + 1 minor or 3 minor; and Rejected IE if a firm alternative diagnosis is established, criteria resolve with ≤4 days of antibiotics, or criteria for Definite or Possible are not met.
How it works
- Review the two major criteria: positive blood cultures (qualifying organisms or persistent bacteremia) and evidence of endocardial involvement on echocardiography or positive 18F-FDG PET.
- Review the five minor criteria: predisposing cardiac condition or IV drug use; fever ≥38 °C; vascular phenomena (emboli, Janeway lesions, mycotic aneurysm); immunologic phenomena (Osler nodes, Roth spots, RF, GN); and microbiologic evidence not meeting a major criterion.
- Check each criterion that is present in the patient.
- The tool tallies major and minor counts in real time and applies the Duke classification rules to return Definite, Possible, or Rejected.
- Use the result alongside clinical judgment — Duke criteria are a diagnostic aid, not a substitute for specialist evaluation.
Use cases
- Rapid bedside classification of suspected endocarditis cases.
- Teaching house officers the major and minor Duke criteria.
- Documenting clinical reasoning for suspected IE in progress notes.
- Deciding on empirical antibiotic therapy urgency before culture results.
- Determining need for urgent echocardiography in high-risk presentations.
- Reviewing criterion weighting for educational or audit purposes.