Skip to main content
. Author manuscript; available in PMC: 2013 Apr 14.
Published in final edited form as: Arch Intern Med. 2009 Mar 9;169(5):463–473. doi: 10.1001/archinternmed.2008.603

Table 1.

Definition of infective endocarditis according to the modified Duke criteria22

Definite infective endocarditis
 Pathologic criteria

  • Microorganisms demonstrated by culture or histologic examination of a vegetation, a vegetation that has embolized, or an intracardiac abscess specimen; or

  • Pathologic lesions; vegetation or intracardiac abscess confirmed by histologic examination showing active endocarditis

 Clinical criteria (see below for definitions)

  • 2 major criteria; or

  • 1 major criterion and 3 minor criteria; or

  • 5 minor criteria

Possible infective endocarditis

  • 1 major criterion and 1 minor criterion; or

  • 3 minor criteria

Rejected

  • Firm alternate diagnosis explaining evidence of infective endocarditis; or

  • Resolution of infective endocarditis syndrome with antibiotic therapy for ≤4 days; or

  • No pathologic evidence of infective endocarditis at surgery or autopsy, with antibiotic therapy for ≤4 days; or

  • Does not meet criteria for possible infective endocarditis, as above

Definition of terms used in the modified Duke criteria for the diagnosis of infective endocarditis (IE):
Major criteria
 Blood culture positive for IE

  • Typical microorganisms consistent with IE from 2 separate blood cultures:

  • Viridans streptococci, Streptococcus bovis, HACEK group, Staphylococcus aureus; or

  • Community-acquired enterococci, in the absence of a primary focus; or

  • Microorganisms consistent with IE from persistently positive blood cultures, defined as follows:

  • At least 2 positive cultures of blood samples drawn >12 h apart; or

  • All of 3 or a majority of ≥4 separate cultures of blood (with first and last sample drawn at least 1 h apart)

  • Single positive blood culture for Coxiella burnetii or antiphase I IgG antibody titer >1:800

 Evidence of endocardial involvement
 Echocardiogram positive for IE (TEE recommended in patients with prosthetic valves, rated at least “possible IE” by clinical criteria, or complicated IE [paravalvular abscess]; TTE as first test in other patients), defined as follows:

  • Oscillating intracardiac mass on valve or supporting structures, in the path of regurgitant jets, or on implanted material in the absence of an alternative anatomic explanation; or

  • Abscess; or

  • New partial dehiscence of prosthetic valve

 New valvular regurgitation (worsening or changing of pre-existing murmur not sufficient)
Minor criteria

  • Predisposition, predisposing heart condition or injection drug use

  • Fever, temperature >38°C

  • Vascular phenomena, major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhages, and Janeway's lesions

  • Immunologic phenomena: glomerulonephritis, Osler's nodes, Roth's spots, and rheumatoid factor

  • Microbiological evidence: positive blood culture but does not meet a major criterion as noted abovea or serological evidence of active infection with organism consistent with IE

  • Echocardiographic minor criteria eliminated

Abbreviations: TEE, transesophageal echocardiography; TTE, transthoracic echocardiography.

a

Excludes single positive cultures for coagulase-negative staphylococci and organisms that do not cause endocarditis.