A Rare Case of Acute Bacterial Native Valve Endocarditis Caused by Streptococcus thoraltensis

This report presents a rare case of acute bacterial native valve endocarditis caused by Streptococcus thoraltensis in a 57-year-old male with a history of intravenous drug use. The patient presented with chest pain, productive cough, and diarrhea, with clinical evaluation revealing atrial flutter, pulmonary embolism, and a large tricuspid valve vegetation. Blood cultures confirmed Streptococcus thoraltensis, an organism rarely implicated in human infections. The patient's prior work at an animal shelter, with direct handling of rabbits, suggests a possible zoonotic transmission of the infection. Treatment with intravenous ceftriaxone resulted in partial clinical improvement, but the patient was lost to follow-up. This case highlights the importance of considering rare pathogens in endocarditis, particularly in patients with exposure to animals or intravenous drug use. It underscores the need for thorough patient history in guiding diagnosis and treatment. It adds to the limited literature on Streptococcus thoraltensis as a human pathogen, emphasizing the need for increased awareness and documentation.