From the Guidelines
The Modified Duke Criteria are used to diagnose infective endocarditis, and they include major criteria such as positive blood cultures for typical microorganisms and evidence of endocardial involvement on echocardiography, as well as minor criteria like predisposition, fever, and vascular phenomena 1.
Major Criteria
- Blood cultures positive for IE:
- Typical microorganisms consistent with IE from two separate blood cultures: Viridans streptococci, Streptococcus bovis, HACEK group, Staphylococcus aureus; or community-acquired enterococci in the absence of a primary focus
- Microorganisms consistent with IE from persistently positive blood cultures: at least two positive blood cultures of blood samples drawn 12 h apart; or all of three or a majority of > 4 separate cultures of blood (with first and last sample drawn at least 1 h apart)
- Single positive blood culture for Coxiella burnetii or anti–phase 1 IgG antibody titer > 1 : 800
- Evidence of endocardial involvement:
- Echocardiography positive for IE: vegetation, abscess, new partial dehiscence of prosthetic valve, new valvular regurgitation
Minor Criteria
- Predisposition: predisposing heart condition, injection drug use
- Fever: temperature ≥ 38°C
- Vascular phenomena: major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhages, conjunctival hemorrhages; Janeway lesions
- Microbiological evidence: positive blood culture but does not meet major criterion or serological evidence of active infection with organism consistent with IE
- Immunologic phenomena: glomerulonephritis, Osler's nodes; Roth's spots, rheumatoid factor
Diagnosis of IE is definite in the presence of:
- 2 major criteria;
- 1 major and 3 minor criteria;
- 5 minor criteria 1.
From the Research
Definition of Modified Duke Criteria
The Modified Duke Criteria are a set of diagnostic criteria used to diagnose infective endocarditis (IE) 2, 3, 4, 5, 6.
Components of the Modified Duke Criteria
The criteria include:
- Major criteria:
- Minor criteria:
- Predisposition, such as heart condition 3, 5
- Fever 3, 5
- Vascular phenomena, major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhages, and Janeway’s lesions 3
- Immunologic phenomena: glomerulonephritis, Osler’s nodes, Roth’s spots, and rheumatoid factor 3
- 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 3
Diagnosis of Infective Endocarditis
Using the Modified Duke Criteria, IE can be classified into three categories:
- Definite IE: 2 major criteria or 1 major and 2 minor criteria or 5 minor criteria 3, 5
- Possible IE: 1 major and 1 minor criterion or 3 minor criteria 3, 5
- Rejected IE: fewer than 3 minor criteria or firm alternative diagnosis or incomplete criteria due to insufficient investigation, but not meeting the criteria for possible or definite IE 3, 5
Evaluation of the Modified Duke Criteria
Studies have evaluated the performance of the Modified Duke Criteria in diagnosing IE, with reported sensitivities ranging from 63% to 88% and specificities ranging from 50% to 100% 2, 3, 4, 5, 6. The criteria have been updated, and the 2023 Duke-ISCVID criteria have been shown to have slightly improved sensitivity compared to previous criteria 6.