Modified Duke criteria

• Diagnostic criteria for infective endocarditis

Criteria

Major criteria

• Blood culture positive for IE
  • Typical bacteria from 2 separate blood cultures
    • Viridans group streptococci, Streptococcus bovis, HACEK group, Staphylococcus aureus
    • Community-acquired enterococci in the absence of another focus
  • Consistent organisms with persistently-positive blood cultures
    • ≥2 positive cultures drawn >12 h apart
    • 3 or a majority of ≥4 cultures positive, with first and last sample drawn at least 1 h apart
  • Single positive blood culture for Coxiella burnetii or antiphase I IgG antibody titre >1:800
• Evidence of endocardial involvement
  • Echocardiogram positive for IE
  • New valvular regurgitation

Minor criteria

• Predisposing heart condition (mitral valve prolapse, prior infective endocarditis, or bicuspid aortic valve) or injection drug use
• Fever >38ºC
• Vascular phenomena
  • Major arterial emboli
  • Septic pulmonary infarcts
  • Mycotic aneurysm
  • Intracranial hemorrhage
  • Conjunctival hemorrhage
  • Janeway lesions
• Immunologic phenomena
  • Glomerulonephritis
  • Osler nodes
  • Roth spots
  • Rheumatoid factor
• Positive blood cultures not meeting a major criterion, or consistent serology that is not Coxiella

Interpretation

• Definite infective endocarditis if meets pathologic criteria, or if one of:
  • 2 major, or
  • 1 major and 3 minor, or
  • 5 minor
• Possible infective endocarditis if one of
  • 1 major and 1 minor, or
  • 3 minor