Abstract 16036: Concomitant Culture-Negative Left-Sided Native Valve Endocarditis With Splenic Emboli and Babesiosis: A Case Report

Abstract

Description of Case: A 76-year-old man with type 2 diabetes and a previously drained hepatic abscess presented with 3 days of fevers and chills associated with dizziness, weakness, and fatigue after hiking at a New York State Park. He denied any shortness of breath, chest pain, abdominal pain, diarrhea, skin rashes, insect bites, IV drug use, recent travel or sick contacts but reported having dental work one month prior to admission. Initial vital signs were notable for a fever of 38.4°C with a blood pressure of 145/76, heart rate of 90, and physical examination was unremarkable. Extensive laboratory studies were drawn, which initially were notable for normocytic anemia, thrombocytopenia, low haptoglobin and elevated lactate dehydrogenase. Empiric antibiotics were initiated as the patient met criteria for systemic inflammatory response syndrome (SIRS). CT abdomen and pelvis was remarkable for right-sided spleen with polysplenia and multiple peripheral wedge-shaped splenic infarcts. A transthoracic echocardiogram (TTE) was inconclusive for infective endocarditis (IE). A subsequent transesophageal echocardiogram (TEE) showed vegetations on the aortic and mitral valves with mild regurgitation respectively. After cardiothoracic surgery evaluation, he was deemed not a surgical candidate. Blood and urine cultures remained negative, but the Babesia antibodies IgM and IgG antibodies, and Babesia microti PCR was detected. He was started on atovaquone 750 mg twice daily and azithromycin 250 mg once daily for 10 days for babesiosis. He was discharged on vancomycin 1g every 12 hours and ceftriaxone 2g every 24 hours for a total of 6 weeks for empiric IE treatment given splenic emboli. Discussion : We describe a rare case of fever caused by culture-negative mitral and aortic valvular endocarditis with splenic emboli and babesiosis. Recent dental work and hiking outdoors in the Northeast United States of America were the key predisposing factors. Given splenic infarcts, pursuing a TEE was pivotal in ascertaining the diagnosis. The patient received empiric IE treatment for gram-positive cocci, HACEK organisms and babesiosis with improvement of symptoms. Identifying and treating unusual causes of fever and SIRS are crucial in reducing mortality and morbidity.