Case Report: Native aortic valve Listeria monocytogenes endocarditis in an adult with Evans syndrome

TL;DR

A man with Evans syndrome developed a rare Listeria infection in his heart valve, highlighting the risks of long-term immunosuppression and the need for prompt diagnosis and treatment.

Contribution

First reported case of native-valve Listeria monocytogenes endocarditis in a patient with Evans syndrome.

Findings

The patient showed rapid improvement with high-dose intravenous ampicillin after Listeria was identified.

Echocardiography revealed multiple small vegetations on the aortic valve without heart failure or embolic complications.

Discontinuation of immunosuppressants led to sustained remission of Evans syndrome and no infection recurrence.

Abstract

Listeria monocytogenes is an uncommon cause of infective endocarditis but is associated with a high morbidity and mortality rate in immunocompromised hosts. Evans syndrome, typically treated with prolonged high-dose corticosteroids and additional immunosuppressants, may predispose patients to severe opportunistic infection.

A 44-year-old man with Evans syndrome on prednisolone and azathioprine, and with recent disseminated cryptococcosis, presented with acute right upper quadrant abdominal pain after ingesting oyster-containing street food. The patient did not exhibit any fever or neurological symptoms. Laboratory tests showed leukocytosis, thrombocytopenia, elevated inflammatory markers, and mild renal and hepatic dysfunction. Abdominal computed tomography (CT) findings were unremarkable. Empirical cefoperazone/sulbactam was initiated for suspected intra-abdominal infection and escalated to meropenem because of clinical deterioration. Blood cultures subsequently grew Listeria monocytogenes, prompting a de-escalation to high-dose intravenous ampicillin, resulting in rapid symptomatic improvement. Transthoracic and transesophageal echocardiography revealed multiple small, oscillating vegetations on the native aortic valve, consistent with infective endocarditis, without heart failure or embolic complications. The patient completed a 6-week course of ampicillin therapy. Follow-up transesophageal echocardiography showed partial resolution of the vegetations. The corticosteroids and azathioprine were gradually tapered and then discontinued, with sustained remission of Evans syndrome and no recurrence of invasive infections.

This case likely represents the first reported instance of native-valve Listeria monocytogenes endocarditis in a patient with Evans syndrome. It highlights prolonged immunosuppression in Evans syndrome as a potential risk context for invasive listeriosis with cardiac involvement. Early blood culture, routine echocardiographic evaluation for Listeria bacteremia, and timely targeted therapy are essential for optimizing patient outcomes.

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