Duke Criteria for Infective Endocarditis Interpreter
Duke Criteria for Infective Endocarditis Interpreter
The 2023 Duke-ISCVID criteria, classified by the published conjunctions rather than by a points total — with what the 1994, 2000 and 2015 versions counted differently, because the same case can come out definite under one and possible under another.
Duke-ISCVID 2023 classification
Conjunctions, not a sumOne major criterion met (two blood culture sets positive for Staphylococcus aureus); three minor criteria met (prosthetic aortic valve, fever 38.4 °C, splenic abscess on CT); no pathologic specimen; no rejection criterion
The conjunctions, and which version you are using
Possible = 1 major + 1 minor OR 3 minor · Rejected = any of four criteria, including failing the above
- the arithmetic has not changed since 1994
- the four routes to definite are the same in the 1994 Duke criteria, the 2000 modified Duke criteria and the 2023 Duke-ISCVID criteria. What changed is what counts as a criterion, and that is why the same case can be definite under one version and possible under another. The one genuine change to the algebra was in 2000, when “possible” stopped being a residual category and became the numeric rule used here
- what 2000 changed from 1994
- Staphylococcus aureus bacteraemia became a major criterion irrespective of whether it was hospital or community acquired; serological evidence for Coxiella burnetii moved from a minor criterion to a major one; the minor criterion for an echocardiogram “consistent with IE but not meeting major criteria” was removed; and “possible” was redefined as 1 major plus 1 minor, or 3 minor
- what 2015 changed
- the European Society of Cardiology’s 2015 modification added paravalvular lesions on cardiac CT as a major imaging criterion, and abnormal activity around a prosthetic valve on FDG-PET/CT more than three months after implantation. So a European chart from 2016 to 2023 may be using criteria that are neither the 2000 set nor the 2023 set
- what 2023 changed
- a third domain — surgical — was added to the microbiologic and imaging domains, with intraoperative inspection as a major criterion; cardiac CT and FDG-PET/CT became major imaging criteria outright; PCR, amplicon or metagenomic sequencing from blood for C. burnetii, Bartonella species or Tropheryma whipplei became a major microbiologic criterion; the requirements for timing and separate venipunctures for blood cultures were removed; the list of typical organisms was expanded, including Enterococcus faecalis and Staphylococcus lugdunensis; predisposing conditions were expanded to include transcatheter valves, endovascular cardiac implantable electronic devices and prior endocarditis; and rejection criterion B was reworded
- performance
- in 595 consecutive adults referred to the endocarditis team at Amsterdam University Medical Center between October 2016 and March 2021, with an international expert panel’s diagnosis as the reference, the 2023 criteria were 84.2 per cent sensitive against the modified Duke criteria’s 74.9 per cent. Those two figures were read in a summary of the validation paper rather than in the paper itself, and the summary does not say whether they refer to “definite” alone or to “definite or possible” — so treat the pair as a comparison rather than as an absolute
- what the criteria are for
- the ISCVID states the purpose plainly: “The primary goal of the 2023 Duke-ISCVID IE diagnostic criteria is to catalyze research in IE by providing an internationally reproducible definition of the syndrome”, and “these guidelines are intended to supplement but never replace clinical judgment”. A classification is not a diagnosis and this page renders neither
Worked example
One major criterion met (two blood culture sets positive for Staphylococcus aureus); three minor criteria met (prosthetic aortic valve, fever 38.4 °C, splenic abscess on CT); no pathologic specimen; no rejection criterion
Pathologic criteria not met, so the clinical criteria decide
No rejection criterion applies
One major criterion, three minor criteria — the published conjunction "1 major + 3 minor" is satisfied, so the case is definite
Change the major count to two and the minor count to zero and the answer is still definite, by a different conjunction. The instrument does not add: two is not more than four here, it is a different kind of evidence
Change the major count to zero and leave four minor criteria — the same "total" of four — and the answer drops to possible
Drop to one major and no minor criteria and the answer is rejected by criterion D, which is a statement about the criteria rather than about the patient
Under the 2000 modified Duke criteria the same case might have had a different major count: the splenic abscess on CT is a minor vascular phenomenon in both versions, but a paravalvular lesion seen only on cardiac CT was not a major criterion before 2015 and FDG-PET/CT was not one before 2023
The 2023 Duke-ISCVID major clinical criteria
| Domain | Criterion |
|---|---|
| Microbiologic — blood cultures | Two or more separate positive blood culture sets for organisms typical of endocarditis, or three or more for organisms that rarely cause it. The 2000 requirements for timing and separate venipunctures have been removed |
| Microbiologic — molecular | PCR or other nucleic acid detection of Coxiella burnetii, Bartonella species or Tropheryma whipplei in blood |
| Microbiologic — serology | C. burnetii IgG titre above 1:800, or one positive blood culture for it; or indirect immunofluorescence showing IgM and IgG to Bartonella henselae or B. quintana with an IgG titre above 1:800 |
| Imaging — anatomical | Echocardiography or cardiac CT showing vegetation, valve perforation or aneurysm, abscess, pseudoaneurysm or intracardiac fistula |
| Imaging — regurgitation | Echocardiography showing significant new valvular regurgitation. Worsening or change of pre-existing regurgitation is explicitly not sufficient |
| Imaging — prosthesis | New partial dehiscence of a prosthetic valve against prior imaging |
| Imaging — metabolic | FDG-PET/CT showing abnormal metabolic activity in a native or prosthetic valve, an ascending aortic graft with valve involvement, intracardiac device leads or other prosthetic material |
| Surgical — new in 2023 | Evidence of infective endocarditis observed on direct inspection during cardiac surgery |
The 2023 Duke-ISCVID minor criteria, by category
| Category | What counts |
|---|---|
| Predisposition | Prior endocarditis; prosthetic valve; previous valve repair; congenital heart disease; more than mild regurgitation or stenosis of any cause; an endovascular cardiac implantable electronic device; hypertrophic obstructive cardiomyopathy; injection drug use |
| Fever | 38.0 °C or above |
| Vascular phenomena | Arterial embolism; septic pulmonary infarction; cerebral or splenic abscess; mycotic aneurysm; intracranial haemorrhage; conjunctival haemorrhage; Janeway lesions; purulent purpura — including those found only on imaging |
| Immunologic phenomena | Immune complex glomerulonephritis; Osler nodes; Roth spots; rheumatoid factor |
| Microbiologic, short of major | A blood culture growing an organism consistent with endocarditis; or a positive culture or nucleic acid test from a sterile site other than cardiac tissue, a cardiac prosthesis or an arterial embolus; or a single skin bacterium detected by PCR on a valve or lead with no other supporting evidence |
| Imaging, short of major | FDG-PET/CT activity in a valve, graft, device lead or prosthetic material within 3 months of implantation |
| Physical examination | Where echocardiography is unavailable, auscultatory evidence of new valvular regurgitation. Worsening of pre-existing regurgitation is not sufficient |
Three revisions, one unchanged piece of logic
The Duke criteria have been revised twice and the version matters. The original 1994 set defined definite endocarditis by pathologic criteria or by one of three conjunctions — two major, one major with three minor, or five minor — and left possible as a residual: anything consistent with endocarditis that was neither definite nor rejected. The 2000 modification by Li and colleagues kept the three routes to definite, made Staphylococcus aureus bacteraemia a major criterion whatever its source, promoted Coxiella burnetii serology from minor to major, deleted the minor echocardiographic criterion, and replaced the residual possible with a numeric rule. The European Society of Cardiology added cardiac CT and PET findings in 2015. The 2023 Duke-ISCVID revision, adopted by that year’s ESC endocarditis guideline, is the version this page implements.
What 2023 changed is substantial and almost all of it is microbiological and radiological. A third domain — surgical — joined microbiologic and imaging, with direct inspection at operation becoming a major criterion in its own right. Cardiac CT and FDG-PET/CT became major imaging criteria outright. Molecular detection of C. burnetii, Bartonella species or Tropheryma whipplei from blood became a major microbiologic criterion. The old requirements about the timing of blood cultures and separate venipunctures were removed. The list of typical organisms grew to include Enterococcus faecalis and Staphylococcus lugdunensis, and the list of predisposing conditions grew to include transcatheter valves and endovascular devices.
The arithmetic, by contrast, has not moved since 1994, and it is not arithmetic. This instrument does not sum: two major criteria and one major with three minor criteria reach the same classification, while four minor criteria alone — the same “total” as one major and three minor — reach only possible. A major criterion is a different kind of evidence from a minor one, not three of them. Nothing on a single numeric scale reproduces those relations, which is why this page is an interpreter over the published conjunctions and not a score.
The practical consequence of three live versions is that the same case can be classified differently depending on which set is applied, and the direction is predictable: the newer criteria capture more. In an external validation of 595 consecutive adults referred to the endocarditis team at Amsterdam University Medical Center between October 2016 and March 2021, judged against an international expert panel’s diagnosis, the 2023 criteria reached 84.2 per cent sensitivity against the modified Duke criteria’s 74.9 per cent. Both leave true cases uncaptured. These criteria classify a case; they do not diagnose one. Their stated purpose is an internationally reproducible definition for research, and the 2023 revision says in terms that it is “intended to supplement but never replace clinical judgment”. Every figure here comes from a named cohort, and cohorts differ in case mix, era, outcome definition and treatment; where your own institution’s protocol differs, it takes precedence. This page reports published figures and recommends no action.
Frequently asked questions
Which version of the Duke criteria does this page use?
The 2023 Duke-ISCVID criteria, which the 2023 ESC infective endocarditis guideline adopted. The tables above list the 2023 major and minor criteria in full, and the formula section states what the 1994, 2000 and 2015 versions counted differently. If you are reading an older record, check which set was applied before comparing classifications.
Why is one major plus three minor definite, while four minor alone is only possible?
Because the criteria are conjunctions, not a sum. A major criterion is evidence of endocardial involvement or of a characteristic organism; a minor criterion is a predisposition or a consequence. The instrument has never treated one major as worth three minors in general — it specifies which combinations qualify, and “1 major + 3 minor” is on the list while “4 minor” is not.
Does a rejected classification mean the patient does not have endocarditis?
No. Three of the four rejection criteria say something positive — a firm alternative diagnosis, or improvement or a negative operation on less than four days of antibiotics — but the fourth is simply “does not meet criteria for possible IE”, which is a statement about the evidence collected so far. The external validation put the 2023 criteria’s sensitivity at 84.2 per cent against an expert panel, so roughly one true case in six falls outside them.
How do I count minor criteria?
By category, not by finding. The six countable categories are predisposition, fever at or above 38.0 °C, vascular phenomena, immunologic phenomena, microbiologic evidence short of a major criterion, and imaging short of a major criterion. A patient with Osler nodes, Roth spots and a positive rheumatoid factor has one minor criterion, not three. The seventh row in the table above — auscultatory new regurgitation — counts only where echocardiography is unavailable.
Where does pathological confirmation fit?
Outside the clinical criteria. Organisms or active endocarditis identified in a vegetation, in cardiac tissue, on an explanted valve or sewing ring, in an ascending aortic graft with valve involvement, on an intracardiac device or in an arterial embolus makes the case definite on its own, whatever the major and minor counts are. That is why this page asks for it first and ignores the counts when it is present.
Related calculators
References
- Fowler VG Jr, Durack DT, Selton-Suty C, et al. The 2023 Duke-International Society for Cardiovascular Infectious Diseases Criteria for Infective Endocarditis. Clin Infect Dis. 2023;77(4):518–526 (correction 2023;77(8):1222). Tables 1–3 read in full as real text.
- The Merck Manuals’ reproduction of Table 2 of the 2023 Duke-ISCVID criteria, read as the independent corroboration of the major and minor criteria.
- Li JS, Sexton DJ, Mick N, et al. Proposed modifications to the Duke criteria for the diagnosis of infective endocarditis. Clin Infect Dis. 2000;30:633–638. Its criteria were read in the European Society of Cardiology’s reproduction and in an open-access 2024 review, not in the paper itself.
- A 2024 open-access review in Frontiers in Cardiovascular Medicine tracing the 1994, 2000, 2015 and 2023 criteria sets, which is the source for what each revision changed.
- External validation of the 2023 Duke-ISCVID criteria in 595 consecutive adults referred to the endocarditis team at Amsterdam University Medical Center, October 2016 to March 2021, against an international expert panel’s diagnosis (Clin Infect Dis. 2024). The sensitivities quoted here — 84.2 per cent against the modified Duke criteria’s 74.9 per cent — were read in JournalFeed’s summary of that paper, not in the paper.
Not medical advice. For healthcare professionals and education. Reference intervals vary by laboratory and assay — always use your own laboratory's. Never base a dose or a treatment decision on this page alone. Full disclaimer at calcengines.com/disclaimer/