The Duke classification for IE is outlined below:
Major criteria
A. Positive blood culture for IE
1. Typical microorganism consistent with IE from two separate blood cultures, as noted below:
- Viridans streptococci, Streptococcus bovis, or HACEK* group, or
- Community-acquired Staphylococcus aureus or enterococci, in the absence of a primary focus
OR
2. Microorganisms consistent with IE from persistently positive blood cultures defined as:
- Two positive cultures of blood samples drawn >12 hours apart, or
- All of three or a majority of four separate cultures of blood (with first and last sample drawn 1 hour apart)
B. Evidence of endocardial involvement
1. Positive echocardiogram for IE defined as:
- Oscillating intracardiac mass on valve (vegetation), or
- Abscess, or
- New partial dehiscence of prosthetic valve
OR
2. New valvular regurgitation (worsening or changing of pre-existing murmur not sufficient)
Minor criteria
- Predisposition: predisposing heart condition or intravenous drug use
- Fever: temperature >38.0° C
- Vascular phenomena: major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial haemorrhage, conjunctival haemorrhages, and Janeway lesions
- Immunologic phenomena: glomerulonephritis, Osler’s nodes, Roth spots, and rheumatoid factor
- Microbiological evidence: positive blood culture but does not meet a major criterion as noted above or serological evidence of active infection with organism consistent with IE
- Echocardiographic findings: consistent with IE but do not meet a major criterion as noted above
Clinical criteria for IE
Clinical criteria for IE requires:
- Two major criteria, or
- One major and three minor criteria, or
- Five minor criteria