Definition of Clinical Criteria of the Duke Classification With Addition of the Modified Duke Criteria (in Boldface)

Major criteriaPositive blood culture (BC)
 2 separate positive BCs consistent with IE (V. streptococci, Streptococcus bovis, HACEK group, S. aureus, and enterococci) in the absence of a primary focus
 ≥2 positive BCs drawn >12 hours apart or ≥4 positive BCs irrespective of the timing
1 positive BC for C. brunetii or antiphase-I immunoglobulin G antibody titer >1:800
Evidence of endocardial involvement
 Positive echocardiogram (TEE recommended in prosthetic valves, rated at least possible IE by clinical criteria, or complicated IE; TTE as the first test in other patients):
  Vegetation on valve or supporting structure
  New partial dehiscence of prosthetic valve
 New valvular regurgitation
Minor criteriaPredisposition
Vascular phenomena (major arterial emboli; intracranial or conjunctival hemorrhage, or Janeway’s lesions)
Immunologic phenomena (glomerulonephritis, Osler’s node, Roth’s spots, or rheumatoid factor)
Microbiological evidence: positive BC that does not meet major criteria or serological evidence of infection
Echocardiographic minor criteria eliminated