Double valve infective endocarditis due to Capnocytophaga canimorsus

Area of Science:

• Cardiology
• Infectious Diseases
• Microbiology

Background:

• Capnocytophaga canimorsus, a Gram-negative bacterium residing in canine oral flora, is an uncommon pathogen in humans.
• Infective endocarditis (IE) typically involves bacterial seeding of heart valves, leading to significant morbidity and mortality.

Observation:

• A 76-year-old male presented with native aortic and mitral valve endocarditis.
• The patient developed a ventricular-atrial fistula, a rare and severe complication of IE.
• Blood cultures were negative, complicating the initial etiological diagnosis.

Findings:

• Infective endocarditis was confirmed to be caused by Capnocytophaga canimorsus.
• The patient received a treatment regimen combining intravenous antimicrobials and surgical intervention.
• Successful clinical outcome was achieved following the integrated treatment approach.

Implications:

• Capnocytophaga canimorsus should be considered in the differential diagnosis of infective endocarditis, particularly in patients with negative blood cultures.
• Asplenic individuals and those with a history of animal exposure (e.g., dog bites or scratches) are at increased risk.
• Early recognition and appropriate management, including antimicrobial therapy and potential surgical repair, are crucial for favorable outcomes in C. canimorsus IE.