Table 1 .

Duke criteria for the diagnosis of infective endocarditis and proposed modifications

Duke criteria		Suggested modifications
Pathological criteria
Microorganisms demonstrated by culture or histological examination
Active endocarditis demonstrated by histological examination
Major criteria
Positive blood cultures		To be added:
–typical microorganisms consistent with endocarditis from two separate blood cultures		–positive serology for Coxiella burnetti7,8
–microorganisms consistent with endocarditis from persistently positive blood cultures		–bacteraemia due to Staphyloccocus aureus8
Evidence of endocardial involvement		–positive molecular assay for specific gene targets and universal loci for bacteria and fungi13
–echocardiography: oscillating structures, abscess formation, new partial dehiscence of prosthetic valve
		–positive serology for Chlamydia psittaci9
–new valvar regurgitation		–positive serology for Bartonella species9
Minor criteria
–predisposing heart disease		To be omitted:
–fever >38°C		Suspect echocardiography (no major criterion)8
–vascular phenomena		To be added:
–immunological phenomena		Elevated CRP, elevated ESR, splenomegaly, haematuria, clubbing, splinter haemorrhages, petechiae and purpura6
–microbiological evidence (no major criterion)
–suspect echocardiography (no major criterion)
		Identified IE organism from metastatic lesions12
Categories
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 rejected	1 major and 1 minor criterion positive8
		3 minor criteria positive8
Rejected:	Alternative diagnosis
	Resolution of the infection with antibiotic treatment for ⩽4 days
	No histological evidence

CRP, C reactive protein; ESR, erythrocyte sedimentation rate; IE, infective endocarditis.

Adapted with permission from Naber CK, Erbel R. Heart 2003;89:241–3.