Localizing chronic Q fever: a challenging query

BMC Infectious Diseases

Table 4 Significant differences between patients with proven chronic Q fever and patients with probable and possible chronic Q fever (univariate analysis)*

	Proven chronic Q fever:	Probable and possible chronic Q fever:	Significance (p)
	Number of patients	Number of patients
	(% or range)	(% or range)
Patient characteristics
Number of patients	18	34
Male sex	17 (94%)	19 (56%)	0.04
Symptomatic chronic infection	14 (78%)	2 (6%)	<0.0001
Cardiac valve prosthesis	4 (22%)	0	0.01
Known aneurysm	8 (44%)	1 (3%)	0.0004
Abdominal aortic aneurysm, infrarenal	7 (39%)	0	0.0003
Vascular prosthesis	11 (61%)	4 (12%)	0.004
Co-morbidities	18 (100%)	22 (65%)	0.021
Diagnostic work-up	16 (89%)	17 (50%)	0.04
Positive serum PCR	12 (67%)	0	<0.0001
Positive tissue PCR	6 (33%)	0	0.011
Anti-phase I IgG at diagnosis	4096 (256-65536)	2048 (1024-32768)	0.013
CFT at diagnosis	1280 (0-20480)	320 (40-5120)	0.001
Time to anti-phase I IgG <1024 (months)	23.3 ± 7.9 [n = 4]	9.5 ± 5.2 [n = 13]	0.001
Helpfulness of abdominal ultrasound	4/8 (50%)	0/14 (0%)	0.01
Helpfulness of FDG-PET/CT	10/13 (77%)	0	<0.0001
Antibiotic therapy	18 (100%)	10 (29%)	<0.0001
Mortality during treatment	3/18 (17%)	0	0.037
Ongoing treatment	13/18 (72%)	9/10 (90%)	0.008
Surgery	6 (33%)	0	0.001
Aortic graft surgery^†	4 (22%)	0	0.011
Cardiac valve surgery	2 (11%)	0	NS
Mortality	3 (17%)	0	0.033

^*Adapted from Wegdam-Blans et al. [15].
^†One patient had surgery twice.
Bold texts summarize components of the table.
Abbrevations: PCR polymerase chain reaction, CFT complement fixation test, FDG-PET/CT ¹⁸F- fluorodeoxyglucose positron emission tomography, NS not significant.

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