Duke Criteria for Infective Endocarditis

Major Criteria 1.Positive Blood Culture Typical microorganism consistent with IE from 2 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

Major Criteria or Microorganisms consistent with IE from persistently positive blood cultures defined as: 2 positive cultures of blood samples drawn >12 hours apart, or all of 3 or a majority of 4 separate cultures of blood (with first and last sample drawn 1 hour apart

Major Criteria 2. Evidence of endocardial involvement Positive echocardiogram for IE defined as : oscillating intracardiac mass on valve or supporting structures, in the path of regurgitant jets, or on implanted material in the absence of an alternative anatomic explanation, or abscess, or new partial dehiscence of prosthetic valve or New valvular regurgitation (worsening or changing of preexisting murmur not sufficient)

Minor Criteria: 1.Predisposition: predisposing heart condition or intravenous drug use 2.Fever: temperature > 38.0° C (100.4° F)

Minor Criteria: 3. Vascular phenomena: major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhages, and Janeway lesions

Minor Criteria: Major Arterial Emboli -cerebral infarct from an arterial embolus, which often leads to a hemorrhagic appearance

Minor Criteria: Septic Pulmonary Infarcts -Recent, small, roughly wedge-shaped hemorrhagic pulmonary infarct.

Minor Criteria: Embolism Pulmonary artery with septic emboli in the lumen. These are composed of bacterial clump seen as purplish granules mixed with fibrin When septic emboli lodged, infectious agent can spread out of the vessel causing regional infection resulting in tissue destruction and inflammatory response.

Minor Criteria: Intracranial hemorrhage

Minor Criteria: Conjunctival hemorrhage

Minor Criteria: Janeway lesions These are painless hemorrhagic cutaneous lesions on the palms and soles. They are non-tender, small erythematous or hemorrhagic macular or nodular lesion, only a few millimeters in diameter that are pathognomonic of infective endocarditis, which is due to the deposition of circulating immune complexes in small blood vessels

Minor Criteria: Splinter haemorrhages They are tiny lines that run vertically under nails. In certain conditions (in particular, infective endocarditis), clots can migrate from the affected heart valve and find their way into various parts of the body. If this happens in the finger, it can cause damage to the capillaries resulting in a splinter haemorrhage.

Minor Criteria: 4. Immunologic phenomena: glomerulonephritis, Osler's nodes, Roth spots and rheumatoid factor

Minor Criteria: Osler's nodes – small, raised, swollen, tender areas, bluish or sometimes pink or red, occurring commonly in the pads of the fingers or toes, in the thenar or hypothenar eminences, or the soles of the feet; they are practically pathognomonic of subacute bacterial endocarditis.

Minor Criteria: 5. Microbiological evidence: positive blood culture but does not meet a major criterion as noted above¹ or serological evidence of active infection with organism consistent with IE

Minor Criteria: 6. Echocardiographic findings: consistent with IE but do not meet a major criterion as noted above