Major Criteria

1) Positive blood culture

• Typical microorganism for infective endocarditis from two separate blood cultures Viridans streptococci, Streptococcus bovis, HACEK group or Community-acquired Staphylococcus aureus or enterococci in the absence of a primary focus, or

• Persistently positive blood culture, defined as recovery of a microorganism consistent with infective endocarditis from: Blood cultures drawn more than 12 hours apart, or All of three or a majority of four or more separate blood cultures, with first and last drawn at least 1 hr apart Q fever serology

2) Evidence of Endocardial Involvement

• Positive echocardiogram
• Oscillating intracardiac mass, on valve or supporting structures, or in the path of regurgitant jets, or on implanted material, in the absence of an alternative anatomical explanation, or Abscess, or

• New partial dehiscence of prosthetic valve, or

• New valvular regurgitation (increase or change in preexisting murmur not sufficient)

Minor Criteria
• Predisposition: predisposing heart condition or intravenous drug use
• Fever > 38.0^oC (100.4^oF)
• Vascular phenomena: major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhage, Janeway lesions
• Immunological phenomena: glomerulonephritis, Osler's nodes, Roth's spots, rheumatoid factor
• Microbiological evidence: positive blood culture but not meeting major criterion as noted previously (excluding single positive cultures for coagulase-negative staphylococci and organisms that do not cause endocarditis) or serologic evidence of active infection with organism consistent with infective endocarditis.