Haemophilus influenzae (HI) is an exceedingly rare cause of infective endocarditis (IE).

We present a case of a 90-year-old female diagnosed with HI-IE involving the native tricuspid valve in the absence of traditional risk factors for right-sided endocarditis. She was treated with a 5-week course of IV Ampicillin from negative cultures and suffered no complications. We also conducted a thorough literature review through PubMed and Google Scholar, which yielded a mere 15 reported cases of HI-IE.

Fourteen of the reported HI-IE cases included epidemiological data, showing no gender predominance. The mean age of the subjects was 39.5, with the mitral valve being the most implicated (64%) and tricuspid valve involvement being rare (21%).

Native tricuspid valve IE is an uncommon entity, especially in the absence of IV drug use. Haemophilus influenzae is an extremely rare cause of IE, with a literature review showing merely 15 reported cases. This article cites the 16th case of HI-IE published in the literature.