culture-negative endocarditis

Etiology

• receipt of antibiotics before obtaining blood cultures (most common)
• Bartonella
• Coxiella burnetti
• Brucella
• fungi

Laboratory

• blood cultures, 2 sets from different venipuncture sites
  • when cultures have remained negative for 72 hours, serologic testing for Coxiella, Bartonella, Brucella, fungal pathogens
• microbial cell-free DNA assays with sequencing
  • obtain samples before or as early as possible after initiation of antibiotics
• in cardiac surgery cases, valve tissue should be sent out for bacterial, fungal, & mycobacterial cultures & assessment of microbial ribosomal RNA
• urinalysis:
  • may show hematuria & pyruria of immune-complex glomerulonephritis
• rheumatoid factor may be positive

Radiology

• transthoracic echocardiogram
  • transesophageal echocardiogram if holosytolic murmur of mitral regurgitation
• 18F-FdG PET in n cases with uncertain infectious etiology

Management

• empiric therapy against methicillin-susceptible staphylococci, streptococci, & enterococci

More general terms

• endocarditis