Atypical presentation of right-sided native valve infective endocarditis

A previously healthy 55-year-old man presented to hospital with 10 days of progressive dyspnea with fever, night sweats, and a productive cough and no history of recreational drug use or occupational or animal exposures. His wife had developed similar symptoms 2 weeks earlier but had since recovered. Physical exam revealed a new systolic murmur best heard at the left lower sternal border. Transesophageal echocardiogram demonstrated severe tricuspid regurgitation with a small vegetation. Blood cultures were positive for non-typeable Haemophilus influenzae. This case illustrates the necessity of both timely and proficient diagnosis of H. influenzae infection and the unique challenges associated with detecting H. influenzae-related pathology. Clinicians should be aware of the variable presentations of Haemophilus infection, including respiratory infection, neurological infection, and infective endocarditis. Given the fastidious nature of H. influenzae and variability between subtype pathogenicity, microbiology laboratories require tools to culture and differentiate Haemophilus species.