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    Duke Criteria for Infective Endocarditis

    Diagnostic criteria for endocarditis.
    When to Use
    Why Use

    Suspect IE and consider the Duke Criteria in patients with:

    • Prolonged fever (Fever of Unknown Origin)
    • Fever and vascular phenomena (stroke, limb ischemia, physical findings of septic emboli)
    • Persistently positive blood cultures (2 or more).
    • Prosthetic valves who are febrile.
    • Injection drug users who are febrile.
    • A pre-disposing heart condition who are febrile.
    • Fever with a recent history of hospitalization.
    • Formal criteria to diagnose and stratify patients suspected of having infective endocarditis (IE) into “definite”, “possible”, and “rejected”.
    • Should be applied to patients in whom there is a high clinical suspicion of IE.
    • Negative cultures may be confounded by a recent history of treatment with antibiotics.
    • The IE Mortality Risk Score can help risk stratify patients' 6 month outcome once IE is confirmed.

    Patients with IE can have a wide range of clinical features and the diagnosis can be challenging. This criteria is sensitive for disease detection, and has a high negative predictive value.

    Pathological Criteria

    If either is positive, diagnosis is definite (see Evidence for exceptions)

    Major Clinical Criteria

    If both are positive, diagnosis is definite (see Evidence for exceptions)

    Minor Clinical Criteria

    If all are positive, diagnosis is definite (see Evidence for exceptions)

    Diagnostic Result:

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    Next Steps
    Creator Insights


    The diagnosis of infective endocarditis must be made as soon as possible to initiate therapy.


    • Start antibiotic treatment based on guidelines and microbiology.
    • Identify candidates who need surgical treatment.


    • Use clinical judgment to decide if the patient has IE.
    • Consider trans-esophageal echocardiography (TEE), if not done.
    • Identify candidates who need surgical treatment.
    • Examine the patient regularly to watch for major or minor signs of IE.
    • Examine for physical findings suggestive of IE (Roth’s spots, Osler's nodes, Janeway lesions
    • Draw blood cultures regularly if not positive earlier to look for microbiologic evidence.


    • Consider other causes of fever, like other infectious sources, or rheumatologic or oncologic.


    “Definite” IE:

    • One or more Pathologic criteria, or
    • 2 major criteria, or
    • 1 major and 3 minor criteria, or
    • 5 minor criteria

    “Possible” IE:

    • 1 major criterion and 1 minor criterion, or
    • 3 minor criterion


    • Firm alternative diagnosis explaining evidence of IE, or
    • Resolution of IE symptoms with antibiotics for less than or equal to 4 days, or
    • No pathological evidence of IE at surgery or autopsy, with antibiotic therapy < 4 days, or
    • Does not meet criteria of “possible”, as above.

    Critical Actions

    • Prior treatment with even a few days of antibiotics may mask pathological evidence of IE(micro-organisms in the tissue or histological evidence).
    • Consider trans-esophageal echocardiography if the clinical suspicion is high and the patient is in the “possible” group.
    • Consider IE, if previously not suspected, if persistently positive (2 or more) blood cultures.
    • For patients who have subacute IE and are hemodynamically stable, empiric antibiotics can be avoided so that additional blood cultures can be obtained without the confounding effect of empiric treatment.


    Selection of the appropriate criteria.

    Facts & Figures

    These are technically the “modified” or “revised” Duke Criteria, which were updated in 2000. The updates included:

    • “Possible” IE modified to include patients having 1 major and 1 minor criterion, or 3 minor criteria.
    • Nosocomially acquired Staphylococcus aureus bacteremia  also included.
    • Coxiella burnetii criteria mentioned above included
    • Trans-esophageal echocardiography (TEE)  recommended for patients with prosthetic valves, rated at least “possible” by clinical criteria, or complicated IE (paravalvular abcess); Trans-thoracic echocardiography (TTE) in other patients.
    • Echocardiographic minor criteria eliminated.

    Evidence Appraisal

    • In the original study by Durack et al, 405 consecutive cases of suspected IE in 353 patients were evaluated in a tertiary hospital from 1985 to 1992.
    • Duke Criteria tried to improve on the older von Reyn criteria.
    • 80% of the 69 pathologically confirmed cases were classified as clinically definite endocarditis by Duke Criteria
    • The older criteria(von Reyn) classified only 35(51%) of the 69 pathologically confirmed cases into the probable category(p<0.0001).
    • 12(17%) pathologically confirmed cases were rejected by the older criteria, but none were rejected by the Duke criteria.
    • Of the 150 cases rejected by older criteria, 11 were definite, 87 were probable, and 52 were rejected by the Duke Criteria.
    • Duke Criteria was validated during the late 1990s with 11 major studies which included 1700 geographically and clinically diverse patient groups(adult, pediatric and geriatric patients, patients from the community, those with and without injection drug use, patients with both native and prosthetic valves, and patients treated outside of the United States).
    • It showed high sensitivity(>80%) and a high negative predictive value in these studies
    Dr. David Durack

    About the Creator

    David Durack, MD, is an infectious disease specialist who is affiliated with Duke University Hospital and has practiced for 46 years. He received his medical degree from University of Western Australia Faculty of Medicine. Dr. Durack's clinical interests include public health, endocarditis, meningitis, septicemia, MRSA, influenza, and vaccines.

    To view Dr. David Durack's publications, visit PubMed

    Content Contributors
    • Pranay Aryal, MD
    About the Creator
    Dr. David Durack
    Content Contributors
    • Pranay Aryal, MD