Infective Endocarditis Presenting As Meningeal Syndrome in an Intravenous Drug User: A Diagnostic Challenge

Infective endocarditis (IE) commonly presents with fever, fatigue, and signs of systemic infection. However, atypical neurological manifestations may delay diagnosis, especially in high-risk populations such as intravenous drug users (IVDUs). We report the case of a 48-year-old man with a history of intravenous drug use who presented with fever, abdominal pain, and altered mental status. On examination, the patient had neck stiffness, a petechial rash, and positive Kernig's and Brudzinski's signs, all of which supported the presence of meningeal irritation. Laboratory studies revealed thrombocytopenia, elevated inflammatory markers, and abnormal liver enzymes. Imaging revealed subarachnoid hemorrhage, splenic and renal infarctions. The patient was admitted to intensive care, where he received broad-spectrum antibiotics and supportive therapy. Blood cultures grew <i>Staphylococcus aureus</i>. A cerebrospinal fluid analysis showed signs of meningeal inflammation, and a transthoracic echocardiogram identified a mitral valve vegetation. Despite initial treatment with broad-spectrum antibiotics, the patient persisted with fever and eventually required mitral valve replacement. This case underscores the critical need to maintain a high index of suspicion for left-sided infective endocarditis in IVDUs presenting with septic syndromes and multiorgan involvement. Importantly, the presence of meningeal signs in this patient played a key role in early recognition of central nervous system involvement. IE should be considered even when clinical features initially suggest alternative diagnoses, such as meningeal syndrome, as timely recognition and initiation of appropriate therapy are essential to improve patient outcomes.