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

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.