Endocarditis Due to Cardiobacterium hominis in a 4-Year-Old Boy, Complicated by Right Lower Lobe Pulmonary Artery Mycotic Aneurysm.

The fastidious, slow-growing bacteria of the species designated by the “HACEK” acronym (Haemophilus parainfluenzae, Haemophilus aphrophilus, Haemophilus paraphrophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae) are important causes of gram-negative endocarditis [1]. Haemophilus species account for the largest number of such infections in children, followed by K kingae, then A actinomycetemcomitans [2, 3]. In children, we found no published reports of E corrodens endocarditis and only 2 reports of C hominis endocarditis; 1 in a 17-year-old in the United Kingdom and the other in a 3-year-old in Japan [4, 5]. To our knowledge, we describe here the first reported case of endocarditis due to C hominis in a child in the western hemisphere, and, for this infection, the unique occurrence of a large pulmonary vessel mycotic aneurysm.