Infective endocarditis and brain abscess secondary to Aggregatibacter aphrophilus

Aggregatibacter aphrophilus is a rare cause of infective endocarditis that was first described in 1940 by Khairat et al. and is now classified under the HACEK group of bacteria (Haemophilus spp., Aggregatibacter spp., Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae). There is limited literature describing the extracardiac complications of infective endocarditis caused by this organism. We report a case of a 53-year-old male with no significant past medical history who developed acute infective endocarditis complicated by a brain abscess caused by A. aphrophilus. The patient underwent aspiration of the abscess and treated with a long course of intravenous antimicrobials. This case represents a rare complication of infective endocarditis caused by A. aphrophilus and to the best of our knowledge, is the second reported case in the literature describing such a complication in a previously healthy patient. Although neurological sequela is associated with higher mortality and may be the presenting symptom of infective endocarditis, it may also be clinically silent – only detected upon imaging.