Duke Criteria: Definition, Criterion Types, Classification and Modification

This scheme is used to make the clinical diagnosis of infective endocarditis.

The Duke criteria make up a compassionate and specific diagnostic scheme.

The Duke criteria and transesophageal echocardiography are sensitive and specific tools for diagnosing infective endocarditis.

In 1994, Durack and others proposed a new set of diagnostic criteria for diagnosing infective endocarditis that later became known as the Duke criteria.

These criteria have been validated by the report authors of numerous studies in recent years on a broad spectrum of patients.

A definitive diagnosis can only be made through a histological verification of the presence of pathogens in the heart valves or embolizations.

This verification is only possible when a valve is explanted or post-mortem.


In most cases, the doctor is limited to making a clinical diagnosis with the help of the Duke criteria. This is often not wholly satisfactory, so these criteria are discussed and modified.

Main criteria

Defined positive blood cultures for infective endocarditis

Positive blood culture for organisms typical of infectious endocarditis, isolated from two separate blood cultures:

  • Streptococcus viridans species o Streptococcus gallolyticus.
  • Organismos del Grupo HACEK (Actinobacilius actinomycetemcomitans, Cardiobacterium man, Eikenella Roden, Streptococcus sp Kingella y sp).
  • Staphylococcus aureus.
  • Community-acquired enterococci in the absence of another approach.

Persistently positive blood cultures of organisms not listed above:

  • Two separate positive blood cultures are drawn from samples drawn more than 12 hours apart.
  • Three out of four positive blood cultures even separated from blood (first and last samples drawn 1 hour apart).
  • At least two positive blood cultures before the start of antibiotic treatment.

Evidence of endocardial involvement

1.Echocardiographic evidence of endocarditis.

  • Vegetation is defined as “oscillating intracardiac mass in a valve or support structure, in the path of a regurgitation jet, or implanted material.” without an alternative anatomical explanation.
  • Intracardiac abscess.
  • New dehiscence of a prosthetic heart valve.

2. New valve regurgitation (change in a persistent murmur, the new buzz does not meet the criteria)

Minor criteria

1. There must be a predisposition: a heart condition or intravenous drug use.

2. fever is observed with a temperature greater than 38.0 C or 100.4 F.

3. Presence of vascular phenomena such as:

  • Arterial embolisms.
  • Septic pulmonary infarcts.
  • Mycotic aneurysm.
  • Intracranial hemorrhage.
  • Conjunctival hemorrhages.
  • Janeway injuries.

4. Presence of immunological phenomena such as:

  • Glomerulonephritis
  • Osler nodes.
  • Roth spots.
  • Positive rheumatoid factor.

5. Microbiological evidence (positive blood cultures that do not meet the main criteria) or serological evidence of active infection with an organism compatible with endocarditis, excluding coagulase-negative Staphylococcus and other common contaminants.

6. Echocardiographic findings: compatible with Infectious Endocarditis but not classified as a significant criterion.


It is considered endocarditis when:

One or more pathological criteria or clinical criteria are met

  • Two main criteria are met.
  • One primary criterion and three minor criteria are met.
  • Five minor criteria are met.

Endocarditis is likely to be the case when:

The primary and minor criteria are present. However, they do not fully meet the requirements set out above.

The Duke criteria were initially proposed in 1994 to help establish the diagnosis of endocarditis. Two main criteria and one minor criterion are needed to diagnose endocarditis.

Alternatively, one primary and three minors may be present to establish the diagnosis.

Modification of the duke criteria

The Duke criteria have shortcomings. An often-heard criticism of the Duke criteria is the overly broad categorization of the group “possible infective endocarditis.”

Although the sensitivity and specificity of the Duke criteria for the diagnosis of infective endocarditis have been validated by many investigators, several deficiencies in this scheme persist.

The Duke Infective Endocarditis Database contains prospectively collected records of over 800 definite and possible infective endocarditis cases since 1984.

Databases on echocardiograms and patients with Staphylococcus aureus bacteremia are also maintained at Duke University Medical Center.

In the future, as advances in microbiological and cardiac imaging methods evolve, additional modifications of the Duke criteria are likely to be necessary.

The addition of new criteria will require rigorous prospective evaluation to improve diagnostic sensitivity without compromising specificity.

The Duke criteria are intended only as a clinical guide for diagnosing infective endocarditis and certainly should not replace clinical judgment.