A Case of Methicillin-Sensitive Staphylococcus aureus Septic Arthritis Causing Septic Pulmonary Emboli in a Healthy Young Adult

Disseminated <i>Staphylococcus aureus</i> (<i>S. aureus</i>) infection in healthy adults is uncommon and usually linked to endocarditis, intravenous (IV) drug use, or immunocompromise. I describe a 21-year-old man who presented with acute right hip pain, fever, and difficulty bearing weight. Evaluation revealed right hip septic arthritis complicated by bilateral septic pulmonary emboli (SPE) and right femoral vein thrombosis. Transthoracic and transesophageal echocardiograms showed no evidence of endocarditis. Blood and joint cultures grew methicillin-sensitive <i>S. aureus</i> (MSSA). He completed six weeks of continuous-infusion intravenous cefazolin with good clinical recovery. This case demonstrates that disseminated MSSA infection with septic emboli can arise in immunocompetent adults without endocarditis and emphasizes the need to consider septic arthritis as a potential primary source.