[Bartonella endocarditis associated with glomerulonephritis and neuroretinitis]

Area of Science:

• Infectious Diseases
• Nephrology
• Ophthalmology

Background:

• Blood-culture negative endocarditis presents diagnostic challenges, often mimicking systemic vasculitis.
• Bartonella and Coxiella species are potential etiologies with overlapping clinical features.

Observation:

• A case of Bartonella henselae endocarditis presented with glomerulonephritis and neuroretinitis.
• Blood cultures were negative, but anti-neutrophil cytoplasmic antibodies and anti-proteinase 3 antibodies were positive.
• Serology showed Bartonella positivity with cross-reactivity to Coxiella burnetii.

Findings:

• Etiological diagnosis was confirmed by polymerase chain reaction (PCR) amplification and sequencing of the ribC gene fragment.
• Bartonella henselae was identified as the causative agent.

Implications:

• Accurate etiological diagnosis is crucial for appropriate treatment of Bartonella and Coxiella infections.
• This case highlights the utility of molecular methods like PCR for diagnosing challenging endocarditis cases.
• Combined antibiotic and immunosuppressive therapy, followed by aortic valve replacement, led to favorable outcomes.