Duke Criteria for Endocarditis

Diagnose endocarditis


The Duke criteria are used to rule in or rule out endocarditis.

Endocarditis is felt to be present in the following conditions:

  • Direct evidence of endocarditis based upon histological findings (a pathological criterion)
  • Positive Gram stain results or cultures of specimens obtained from surgery or autopsy (a pathological criterion)
  • 2 major clinical criteria
  • 1 major and any 3 minor clinical criteria
  • 5 minor clinical criteria

'Possible endocarditis' is defined by 1 major and 1 or 2 minor clinical criteria, OR 3 minor clinical criteria

The diagnosis of endocarditis is 'rejected' in any of the following cases:

  • a firm alternate diagnosis is made
  • clinical manifestations resolve after ≤4 days of antibiotic therapy
  • no pathological evidence of infective endocarditis is found at surgery or autopsy after antibiotic therapy for ≤4 days
  • fail to meet criteria for for possible or definite infective endocarditis


Beynon RP, Bahl VK, Prendergast BD.

BMJ: British Medical Journal 2006 August 12, 333 (7563): 334-9

Li JS, Sexton DJ, Mick N, et al.

Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America 2000, 30 (4): 633-8

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1. Blood Culture Positive for IE?

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a) Typical microorganisms consistent with IE from 2 seperate blood cultures:
i. Viridans streptococci, Streptococcus bovis, HACEK group, Staphylococcus aureus
ii. Community-acquired enterococci, in the absence of a primary focus

b) Microorganisms consistent with IE from persistently positive blood cultures, defined as follows:
i. At least 2 positive cultures of blood samples drawn >12 hours apart; or
ii. All of 3 or a majority of 4 separate cultures of blood (with first and last samples drawn at least 1 hour apart)

c) Single positive blood culture for Coxiella Burnetii or antiphase I IgG antibody titer >1:800

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