Acute multifocal retinitis in a patient with Q fever (Coxiella Burnetii infection) with endocarditis

Abstract

Objective: To report acute multifocal retinitis in association with serologically-proven Coxiella (C) Burnetii infection (Q fever) with endocarditis.

Material and methods: A single case report documented with multimodal imaging.

Results: A 67-year-old cattle breeder presented with a 2-week history of persistent fever, headache, and floaters in both eyes. On examination, his best-corrected visual acuity was 20/20, and there was 1+ vitreous cells in both eyes. Bilateral fundus examination showed multiple small superficial white retinal lesions scattered in the posterior pole and midperiphery associated with a few retinal hemorrhages. These retinal lesions did not stain on fluorescein angiography (FA) and showed focal hyperreflectivity and thickening primarily involving the inner retinal layers on optical coherence tomography (OCT). There also was a band-like hyper-reflective area in the middle retina consistent with paramacular acute middle maculopathy. Transthoracic echocardiogram (TTE) showed a mobile echodensity on the anterior aortic leaflet consistent with a diagnosis of endocarditis. Elisa assays performed on paired serum samples collected 2 weeks apart showed increase in antibodies against C burnetii from 60 IU/ml to 255 IU/ml. The patient was treated with doxycycline 100 mg twice a day for 18 months, with subsequent resolution of the endocarditis. Sequential ocular examinations showed gradual resolution of all acute retinal findings without visible scars.

Conclusion: Acute Q fever, caused by C burnetii infection, should be considered in the differential diagnosis of acute multifocal retinitis. A systematic cardiac assessment with echocardiography is essential for early diagnosis of associated endocarditis and for prompt administration of appropriate antibiotic treatment to improve clinical outcomes.

Keywords: Acute Q fever; Acute multifocal retinitis; Coxiella burnetii; endocarditis.

Fig. 1

Baseline composite fundus photography shows bilateral small yellow-white retinal lesions in the posterior pole and the periphery (red arrows), with a few retinal hemorrhages, some of which are white-centered (yellow arrow). Note the presence of an old, flat, well-delineated atrophic and pigmented lesion along the superotemporal retinal vascular arcade in the left eye

Fig. 2

Swept source OCT scan of the LE passing through a retinal infiltrate shows hyperreflective preretinal vitreous dots and a focal area of thickened, hyperreflective inner retina with infiltration extending from the nerve fiber layer to the outer retinal layers, with the ellipsoid zone, retinal pigment epithelium, and choroid clearly delineated and spared (red arrow). Note the presence of a band-like hyperreflective area in the middle retina suggestive of PAMM (yellow arrow)

Fig. 3

Transthoracic echocardiogram shows a mobile echodensity on the anterior aortic leaflet measuring 20 x 14 mm consistent with endocarditis (yellow arrow)

Fig. 4

Fundus photography taken six weeks after initial presentation shows a complete resolution of retinal hemorrhages and multifocal retinal lesions, without visible scarring

Fig. 5

Swept source-OCT scan taken at the same time shows the disappearance of the band-like hyper-reflectivity corresponding to PAMM and a focal area of inner retinal thinning corresponding to a resolved retinal infiltrate (arrow)