1) Microorganisms demonstrated by culture or on histologic examination of a vegetation, a vegetation that has embolized, or an intracardiac abscess specimen; or

2) Pathologic lesions; vegetation or intracardiac abscess confirmed by histologic examination showing active endocarditis.

Major criteria

1) Blood cultures positive for IE:

a) Typical microorganisms consistent with IE from 2 separate blood cultures: viridans group streptococci, Streptococcus gallolyticus (formerly S bovis), HACEK group, Staphylococcus aureus, Enterococcus faecalis; or

b) Microorganisms consistent with IE from persistent positive blood cultures: ≥2 positive blood cultures of samples drawn >12 h apart; or all of 3 or a majority of ≥4 separate blood cultures (first and last drawn ≥1 h apart); or

c) Single positive blood culture for Coxiella burnetii or phase I IgG antibody titer >1:800.

2) Imaging studies positive for IE: Valvular, perivalvular/periprosthetic and foreign material anatomic and metabolic lesions characteristic of IE detected by any of the following imaging techniques:

a) Echocardiography (TTE and TEE).

b) Cardiac CT.

c) FDG-PET/CT(A).

d) WBC SPECT/CT.

Minor criteria

1) Predisposition, eg, predisposing heart condition or IV drug use.

2) Fever (defined as >38 degrees Celsius).

3) Vascular phenomena (including those detected by imaging only): Major arterial emboli, septic pulmonary infarcts, hematogenous osteoarticular septic complications (spondylodiscitis), infectious (mycotic) aneurysm, intracranial hemorrhage, conjunctival hemorrhages, Janeway lesions.

4) Immunologic phenomena: Glomerulonephritis, Osler nodes and Roth spots, rheumatoid factor.

5) Microbiologic evidence: Positive blood culture but not meeting major criteria (above) or serologic evidence of active infection with organism consistent with IE.

Definite IE: 2 major criteria; 1 major criterion and 3 minor criteria; or 5 minor criteria.

Possible IE: 1 major criterion and 1 or 2 minor criteria; or 3-4 minor criteria.

Rejected IE:

1) Firm alternative diagnosis; or

2) Resolution of symptoms suggesting IE with antibiotic therapy for ≤4 days; or

3) No pathologic evidence of IE at surgery or autopsy with antibiotic therapy for ≤4 days; or

4) Not fulfilling the criteria for possible IE, as defined above.