Endocarditis Diagnostic Standard • Modified Duke
Evidence Pending
Select clinical and lab findings to determine IE diagnostic probability.
Guidelines & Evidence
Verified
Last Review: 2026-07-17
When to Use
Clinical Utility
Diagnosis of suspected Infective Endocarditis (IE) in patients with bacteremia or fever of unknown origin.
Standardization of findings across clinical, microbiological, and imaging (Echo/TEE) domains.
Evaluation of patients with new pathologic heart murmurs or embolic events.
How it Works
Major Criteria Detail
| Blood Cultures | Typical IE organisms (e.g. S. viridans, HACEK) from 2 separate cultures. |
| Echocardiogram | Oscillating intracardiac mass, abscess, or new partial dehiscence of prosthetic valve. |
| Serology | Single positive blood culture for Coxiella burnetii or IgG antibody titer > 1:800. |
Minor Criteria Detail
| Predisposition | Prosthetic valve, prior IE, cyanotic CHD, or IV drug use. |
| Vascular | Arterial emboli, septic pulmonary infarcts, Janeway lesions. |
| Immunological | Glomerulonephritis, Osler nodes, Roth spots, Rheumatoid Factor. |
Clinical Pearls
TEE vs. TTE
Transesophageal Echocardiography (TEE) is significantly more sensitive than TTE (90% vs 60%) for detecting vegetations and is mandatory in patients with prosthetic valves or complex anatomy.
Culture-Negative IE
Prior antibiotic use is the most common cause of culture-negative results.
Fastidious organisms (HACEK group) may require extended incubation (>7 days).
Consider Bartonella, Legionella, or Brucella serology if suspicion remains high.
Next Steps
Definite IE Management
01
Initiate prolonged course of IV antibiotics (usually 4–6 weeks).
02
Consult Cardiology and Infectious Disease immediately.
03
Assess for surgical indications (Heart failure, large vegetations >10mm, or fungal IE).
04
Monitor for embolic complications (Stroke, splenic infarct).
The Evidence
Primary Reference
Proposed modifications to the Duke criteria for the diagnosis of infective endocarditis.
Li JS et al. • Clin Infect Dis.. 2000;n=810. The 2000 modification incorporated TEE findings and Coxiella serology, significantly improving sensitivity over the original 1994 Duke criteria.
Origins & History
From Beth Israel to Duke
The journey of IE diagnosis began with the Von Reyn criteria in 1981, which relied heavily on surgery or autopsy. In 1994, Durack and colleagues at Duke University moved the needle toward clinical diagnosis. The "Modified" version we use today (published by Li et al. in 2000) was the first to recognize the diagnostic power of the Transesophageal Echo (TEE), transforming IE from a surgical diagnosis to a bedside one.
Last Comprehensive Review: 2026-07-17