SHM Converge Scientific Abstract ePoster Gallery-A Challenging Case of Disseminated Staphylococcus Aureus Osteomyelitis

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This case describes a 63-year-old woman with poorly controlled diabetes and a prior ASD repair device who presented with several days of low back pain, elevated inflammatory markers, and mild lactic acidosis. Initial MRI of the thoracic and lumbar spine was negative for infection, and because her pain improved, she was discharged. She returned the next day when blood cultures grew methicillin-susceptible Staphylococcus aureus (MSSA), and she was started on IV cefazolin.<br /><br />Despite a negative transthoracic echocardiogram, she had persistent MSSA bacteremia and worsening back pain. Repeat lumbar MRI four days later revealed severe vertebral osteomyelitis, discitis, and bilateral psoas abscesses. The infection had disseminated further, causing septic arthritis of the right shoulder and left knee, requiring incision and drainage and repeated washouts.<br /><br />Because blood cultures remained positive, IV ertapenem was added as salvage therapy for persistent bacteremia. A transesophageal echocardiogram one week later showed new vegetation on the ASD occluder device, suggesting device seeding. Antibiotics were changed to IV nafcillin with continued ertapenem synergy. Cardiothoracic surgery declined device removal due to high operative risk and no cardiac compromise.<br /><br />After two weeks of persistent bacteremia, cultures finally cleared. The patient completed six weeks of outpatient parenteral antibiotic therapy, and follow-up MRI showed marked improvement with resolution of the abscesses. She was placed on lifelong cefadroxil because of the retained ASD device.<br /><br />Key teaching points are that early imaging can miss evolving osteomyelitis, persistent S. aureus bacteremia should prompt aggressive search for occult infection sources, and clinicians must rely on the full clinical picture rather than reassuring imaging alone.

Asset Subtitle

Yusra Azhar

Meta Tag

Author List David Clanon, Sarah Burns, Yusra Azhar

Category Clinical Vignettes

Concept Staphylococcus aureus Bacteremia

Concept Infectious focus

Concept Endocarditis

Concept Metastatic Infection

Concept MSSA infection

Distinguished Non-Finalist

Presenter Organization University of New Mexico School of Medicine, Department of Internal Medicine

Presenting Author Yusra Azhar

Track Adult

Keywords

MSSA bacteremia

vertebral osteomyelitis

discitis

psoas abscess

septic arthritis

ASD occluder device

persistent bacteremia

transesophageal echocardiogram

nafcillin

cefadroxil

Staphylococcus aureus Bacteremia

Infectious focus

Endocarditis

Metastatic Infection

MSSA infection