Table 1.

Modified Duke criteria for diagnosis of infective endocarditis

Major criteria

- Typical microorganism consistent with IE from two separate blood cultures: viridans-group streptococci, Streptococcus bovis, HACEK group, Staphylococcus aureus or community-acquired enterococci, in the absence of a primary focus

OR

- Microorganisms consistent with IE from persistently positive blood cultures defined as:

. Two positive cultures of blood samples drawn >12 h apart, or

. All of three or a majority of four separate cultures of blood (with first and last sample drawn 1 h apart)

OR

- Coxiella burnetii detected by at least one positive blood culture or antiphase I IgG antibody titre >1:800

OR

- Positive echocardiogram showing vegetation, abscess, new valvular regurgitation or new dehiscence of prosthetic valves.

Minor criteria

• Predisposing heart disease, drug injection

• Fever: temperature >38°

• Vascular phenomena: arterial emboli, splenomegaly, mycotic aneurysm, conjunctival haemorrhages, petechiae or purpura

• Immunological phenomena: glomerulonephritis, Osler’s nodes, Roth spots or rheumatoid factor

• Microbiological evidence not fitting major criteria

Definite IE

• Two major criteria

OR

• One major and three minor criteria

OR

• Five minor criteria

Possible IE

• One major criterion and one minor criterion

OR

• Three minor criteria