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Modified Duke Criteria for Infective Endocarditis

Modified Duke criteria (Li 2000) classify infective endocarditis as definite (2 major, 1 major + 3 minor, or 5 minor, or pathological proof), possible (1 major + 1 minor, or 3 minor) or rejected. Major criteria are typical positive blood cultures and echocardiographic/new-regurgitation evidence of endocardial involvement.

  • Major: positive blood cultures (typical organism in 2 separate cultures, persistent bacteremia, or single culture/phase I IgG > 1:800 for Coxiella burnetii) (yes/no, +1)
  • Major: evidence of endocardial involvement (vegetation, abscess, new prosthetic dehiscence on echo, or new valvular regurgitation) (yes/no, +1)
  • Minor: predisposing heart condition or injection drug use (yes/no, +1)
  • Minor: fever ≥ 38.0 °C (yes/no, +1)
  • Minor: vascular phenomena (major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, ICH, conjunctival hemorrhage, Janeway lesions) (yes/no, +1)
  • Minor: immunologic phenomena (glomerulonephritis, Osler nodes, Roth spots, rheumatoid factor) (yes/no, +1)
  • Minor: microbiologic evidence not meeting a major criterion (or serology of active infection) (yes/no, +1)
  • Pathological criteria: organisms or active endocarditis on histology/culture of vegetation, embolus or abscess (yes/no, +1)
  • Rejected: firm alternative diagnosis, or resolution with ≤ 4 days of antibiotics, or no pathological evidence at surgery/autopsy after ≤ 4 days of antibiotics (yes/no, +1)
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Interpretation

ResultMeaning
Definite2 major; or 1 major + 3 minor; or 5 minor; or pathological criteria
Possible1 major + 1 minor; or 3 minor
RejectedFirm alternative diagnosis, resolution with ≤ 4 days of antibiotics, or possible criteria not met

Formula

Major (2): typical positive blood cultures (incl. single Coxiella culture or phase I IgG > 1:800); evidence of endocardial involvement. Minor (5): predisposition/IDU; fever ≥ 38 °C; vascular phenomena; immunologic phenomena; microbiologic evidence not meeting major. Definite = 2M, 1M + 3m, or 5m. Possible = 1M + 1m or 3m.

Clinical pearls

  • The 2023 Duke-ISCVID criteria update these rules: they add PET/CT and cardiac CT imaging, PCR/sequencing, intraoperative inspection as a major criterion, more "typical" organisms, cardiac devices as predispositions, and drop blood-culture timing rules.
  • TEE is more sensitive than TTE for vegetations and abscesses, particularly with prosthetic valves; a negative TTE does not exclude IE when suspicion is high.
  • "Possible IE" still often warrants a full treatment course when S. aureus bacteremia or high clinical suspicion is present.

Examples

duke criteria staph aureus bacteremia with vegetation on teemodified duke: 1 positive blood culture, fever, ivdu, janeway lesionsendocarditis criteria strep viridans in 2 blood cultures, fever, no vegetation on echo

FAQ

What makes infective endocarditis "definite" by Duke criteria?

Two major criteria, one major plus three minor, five minor criteria, or pathological proof from a vegetation, embolus or abscess.

What changed in the modified Duke criteria?

Li 2000 added "possible IE" minimum thresholds (1 major + 1 minor or 3 minor), made S. aureus bacteremia a major criterion regardless of source, added Coxiella serology as major, and removed echocardiographic minor criteria.

Evidence

  1. Li JS et al. Proposed modifications to the Duke criteria for the diagnosis of infective endocarditis. Clin Infect Dis 2000;30:633–8.
  2. Fowler VG et al. The 2023 Duke-ISCVID Criteria for Infective Endocarditis: Updating the Modified Duke Criteria. Clin Infect Dis 2023;77:518–26.

Infectious Disease · Reviewed 2026-10-14 · Methodology