A fatal case of disseminated chronic Q fever: a case report and brief review of the literature

Abstract

Background: Chronic Q fever is a rare infection, which mainly manifests as endocarditis, infection of vascular prostheses or aortic aneurysms. We present the case of a 74-year-old immunocompromised man with a haematologically disseminated Coxiella burnetii infection, which has never been reported before.

Case report: He was diagnosed with a chronic Q fever infection of an aneurysm with an endovascular prosthesis in 2015, but he died despite optimal treatment. Autopsy revealed a disseminated C. burnetii infection, confirmed by a positive PCR on samples from several organs. Retrospectively, he already had complaints and signs of inflammation since 2012, for which he had already been admitted in February 2014. At that time, Q fever diagnostics using PCR, complement fixation assay, and enzyme-linked immunosorbent assay on serum were all negative. In retrospect however, retesting available samples from February 2014 using immunofluorescence assay (IFA) already revealed serology compatible with chronic Q fever.

Conclusion: Clinicians should be aware of this silent killer, especially in case of risk factors, and perform an appropriate diagnostic work-up for Q fever including IFA serology and PCR.

Keywords: Chronic Q fever; Coxiella burnetii; Disseminated infection; Fatal; Q fever.

Fig. 1

¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸FDG-PET) (a), low-dose CT (b), and integrated ¹⁸FDG-PET/CT (c) images, demonstrating increased FDG-uptake in the abscess formation in the left iliopsoas muscle, extending into the intervertebral space cranially of L4 and into the adipose tissue reaching the left abdominal wall. The ¹⁸FDG-PET could not be assessed for disseminated lesions in the brain due to a motion artifact of the head during the procedure

Fig. 2

Transversal integrated ¹⁸F-fluorodeoxyglucose positron emission tomography/low-dose CT (¹⁸FDG-PET/CT) images, from cranial to caudal, demonstrating: a increased FDG-uptake in the left iliopsoas muscle dorsally extending through the musculature of the back, and increased FDG-uptake in the wall of the aortic aneurysm adjacent to the endovascular aneurysm repair (EVAR). b A per continuitatem infection arising from the abdominal aortic aneurysm (AAA), thrombosis of aortic aneurysm and low activity in the cavity of the EVAR resulting from blood flow. The infection extends to the abscess and left iliopsoas muscle. c Percutanous drain in situ in the abscess, increased FDG-uptake in the cranial portion of the vertebra, and increased FDG-uptake in adipose tissue of the left abdominal wall in continuitatem with the abscess (not visible at the level of this transversal slice). d Increased FDG-uptake in the aortic wall adjacent to the caudal part of the EVAR, and increased FDG-uptake extending into adipose tissue of the left abdominal wall

Fig. 3

Cranial view, during autopsy, of the abdominal aorta with the endovascular aneurysm repair (EVAR) stent-graft. The lumen of the celiac trunk and superior mesenteric artery are visible. Around the EVAR the aneurysmatic plaque inside the dilated vascular wall is still in situ, the material was PCR positive for C. burnetii. A fistula from the abdominal aortic aneurysm (AAA) to the psoas abscess was present (not visible on picture). Inside the EVAR an intra-prosthetic deposition of amorphous material is visible