Table 2

 Duke criteria for the diagnosis of infective endocarditis (IE) and proposed modifications

Duke criteriaSuggested modifications
CRP, C reactive protein; ESR, erythrocyte sedimentation rate.
Reproduced from Prendergast17 with permission.
Pathological criteria
Microorganisms demonstrated by culture or histological examination
Active endocarditis demonstrated by histological examination
Major criteria
Positive blood culturesTo be added:
Typical microorganisms consistent with endocarditis from two separate blood culturesPositive serology for Coxiella burnetti
Bacteraemia due to Staphylococcus aureus
Positive molecular assay for specific gene targets and universal loci for bacteria and fungi
Microorganisms consistent with endocarditis from persistently positive blood cultures
Positive serology for Chlamydia psittaci
Evidence of endocardial involvementPositive serology for Bartonella species
Echocardiography: oscillating structures, abscess formation, new partial dehiscence of prosthetic valve
New valvar regurgitation
Minor criteria
Predisposing heart diseaseTo be omitted:
Fever >38°CSuspect echocardiography (no major criterion)
Vascular phenomena
Immunological phenomenaTo be added:
Microbiological evidence (no major criterion)Elevated CRP, elevated ESR, splenomegaly, haematuria, clubbing, splinter haemorrhages, petechiae and purpura
Suspect echocardiography (no major criterion)
Identified IE organism from metastatic lesions
Definite:Pathological criteria positive
or 2 major criteria positive
or 1 major and 2 minor criteria positive
or 5 minor criteria positive
Possible:All cases which cannot be classified as definite or rejected1 major and 1 minor criterion positive
3 minor criteria positive
Rejected:Alternative diagnosis
Resolution of the infection with antibiotic treatment for ⩽4 days
No histological evidence