Kampschreur et al reported the Dutch criteria for chronic Q fever developed after an outbreak in 2007.
Proven chronic Q fever - one or more of the following:
(1) positive PCR for Coxiella burnetii on tissue, serum or plasma AND acute Q fever absent
(2) IFA phase I titer >= 1024 AND definite endocarditis (revised Duke criteria)
(3) evidence of vascular infection on PET/CT, CT, MRI or ultrasound testing
Probable chronic Q fever - both of the following:
(1) IFA phase I IgG titer >= 1024
(2) one or more of the following:
(2a) valvulopathy not meeting modified Duke criteria
(2b) aneurysm, vascular prosthesis or prosthetic valve without signs of infection on imaging
(2c) signs of possible chronic Q fever infection of noncardiac or vascular (?nonvascular) origin
(2d) pregnancy
(2e) clinical symptoms of chronic infection (night sweats, fever, weight loss, hepatosplenomegaly)
(2f) histopathologic proven granulomatous inflammation
(2g) immune disorder
Possible chronic Q fever - both of the following:
(1) IFA phase I IgG titer >= 1024
(2) none of the clinical manifestations listed above
where:
• The pre-test probability was high in the subjects because of the outbreak.
• Some items may be prone to false positive if the pre-test probability was lower: proven item 3; probable items 2c, 2d, 2e
