Infective Endocarditis: Features

Key points

• Diagnosis (Duke criteria; the major/minor structure is retained in the 2023 Duke-ISCVID update): DEFINITE endocarditis = pathological criteria, OR 2 major, OR 1 major + 3 minor, OR 5 minor.
• Major - microbiological: typical IE organisms on blood culture — the 2023 list was expanded to include Staphylococcus aureus, S. lugdunensis, Enterococcus faecalis and most streptococci (except S. pneumoniae and S. pyogenes), plus the HACEK group. The 2023 update removed the old requirement for cultures taken over 12 h apart or from separate venipunctures. Also a single culture / high IgG titre for Coxiella burnetii, and positive PCR/serology for Bartonella and similar.
• Major - imaging/surgical: positive echo (vegetation, abscess, new prosthetic dehiscence) or new valvular regurgitation; the 2023 update added 18F-FDG PET/CT and cardiac CT as major imaging criteria (PET/CT especially around prosthetic material), and intraoperative inspection as a new major surgical criterion.
• Minor: predisposing heart condition, IV drug use, or a cardiac implantable electronic device (CIED, added 2023); fever 38C or higher; vascular phenomena (emboli, septic pulmonary infarcts, mycotic aneurysm, Janeway lesions); immunological phenomena (glomerulonephritis, Osler's nodes, Roth spots); microbiological evidence not meeting a major criterion.

Decision points in this pathway

• Criteria met?

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