Case Presentation: A 20-year-old male with bicuspid aortic valve s/p aortic valvuloplasty and aortic insufficiency presented with 2 months of cough and intermittent lower extremity edema. On initial exam, temp was 100.7ºF, BP 107/40 mmHg, HR 92 bpm. He had a harsh 2/6 systolic ejection murmur over the rightupper sternal border and a 2/6 diastolic murmur over the left mid sternal border. Initial labs revealed anemia without reticulocytosis, proteinuria, and hematuria. BUN was 45 mg/dL, creatinine was 3.2 mg/dL, and BNP was 1,453 pg/mL. Echocardiogram showed a thickened aortic valve, no valvular vegetations, and worsened aortic insufficiency. Renal biopsy revealed immune complex-mediated glomerulonephritis (GN) with 60% crescents. Immunofluorescence was positive for IgG, IgA, IgM, C1q, C3, and kappa and lambda light chains. Blood cultures were negative. However, serum Nexgen sequencing was positive for Bartonella henselae, confirmed with serum DNA PCR. Brain MRA showed a 3mm mycotic aneurysm of the right middle cerebral artery and CTA brain showed a right lateral frontal temporal mycotic aneurysm with complex anatomy. His mycotic aneurysm was clipped, his aortic valve was replaced, he was started on erythropoietin. He completed 8 weeks of IV doxycycline, IV ciprofloxacin, and PO rifampin. After this regimen, his Bartonella titers remained positive. He remains on PO rifampin and doxycycline with the plan to continue both antibiotics until titers are negative. His BUN, creatinine, hemoglobin, and ESR have normalized, he has no neurologic deficits, and his congestive heart failure (CHF) has resolved.
Discussion: Bartonella is a gram negative bacteria that can be transmitted by cats, fleas, lice, or sand fleas. Bartonella is an opportunistic pathogen that has been shown to be associated with cat scratch disease, hepatitis, endocarditis, neuroretinis, bacteremia, and encephalopathy. It can take up to 30 days for Bartonella to grow, if at all. Bartonella is the etiology for up to 30% of culture negative endocarditis cases. Our patient’s presentation of acute glomerulonephritis suggested infectious or autoimmune etiology. His lack of family history of autoimmune disease and absence of rash or joint pain made this less likely. His presentation of CHF with history of bicuspid aortic valve indicated chronic valvular disease. Paired with fever andglomerulonephritis with immune deposition, these symptoms suggested endocarditis. Important and dangerous sequelae of this illness are observed in this patient, including CHF from valvular insufficiency, acute kidney failure secondary to immune complex deposition glomerulonephritis, and mycotic aneurysm secondary to septic emboli.
Conclusions: This case demonstrates the importance of clinical suspicion in the diagnosis of endocarditis. In patients with clinical signs and symptoms of endocarditis with negative blood cultures, PCR sequencing and serologies for Bartonella should be considered.
