RESUMEN
Hemophilus influenzae is a gram-negative bacteria responsible for significant cases of invasive infections, especially in the pediatric population and in immunosuppressed adult patients. Before vaccination, most cases were frequently caused by capsulated or typeable variants. Due to the absence of effective vaccination against the nontypeable variant, it is now responsible for most invasive infections. Predisposing risk factors in adults include asplenia, hypocomplementemia, cancer, human immunodeficiency virus infection, and chronic cardiopulmonary disease. Immunity to the nontypeable variants causing disease is perplexing and not yet wholly described as they are genetically diverse. Infective endocarditis (IE) is a cardiac infection with devastating consequences if not detected earlier and treated appropriately. Gram-positive bacteria are the primary cause of IE overall, followed by gram-negative bacteria. Hemophilus species belong to the HACEK group of gram-negative bacteria responsible for causing IE in the pediatric population more than in adults. Hemophilus species, especially the nontypeable variant, is a rare cause of IE in adults. Here we present a case of IE due to Nontypeable Hemophilus influenzae in a 49-year-old caucasian male with hypocomplementemia.