A 37-year-old African man was transferred to our hospital from an outside facility with an aortic valve vegetation, multiple embolic strokes and possible brain mycotic aneurysm, with concern for fungal endocarditis. He was initially admitted to an outside hospital with chief complaints of progressive shortness of breath and chest pain for 2 weeks with occasional non-drenching night sweats, fatigue, unintentional ten pounds weight loss in the last 6 months and intermittent sharp chest pain radiating to the neck. His past medical history was significant for latent tuberculosis infection and treatment with 9 months of isoniazid was completed 3 months prior to the presentation. The patient's immunization was up to date and he denied tobacco or alcohol consumption, any recent travel, any prior history of sexually transmitted infections, past or recent history of lice infestation, injection drug abuse, incarceration and homelessness as well. Originally from Democratic Republic of Congo and migrated to Indiana, USA a year prior to the presentation, the patient was married and lived with his wife and 3 children. He worked as school teacher in Congo but at the time was working at a donut shop. In Congo, he had a cow at his home and used to drink raw cow's milk. The patient was not taking any medications. On admission, physical examination demonstrated normal vital signs, cachexia, a 4/6 systolic murmur at the apex with radiation to the axilla, palpable thrill, diastolic 3/6 murmur at the apex, Janeway lesions on bilateral feet and soles and L4-L5 lumbar vertebral tenderness to palpation.
Initial laboratory investigations demonstrated WBC count of 5 x 109 cells per liter (with normal differentiation), hemoglobin of 8.9 g/dL, hematocrit of 27%, and 3 sets of negative blood cultures. Transesophageal echocardiogram (TEE) revealed trileaflet aortic valve with a mobile vegetation, severe aortic and mitral regurgitation, mitral valve stenosis and thickening. CT scan of the chest and abdomen showed bilateral pleural effusions, right lung apex nodular opacities, emphysematous changes, no cavitary lesion, cardiomegaly with prominently dilated left atrium, hepatosplenomegaly with periportal lymphadenopathy, and wedge-shaped hypodense lesions within the peripheral spleen. Left pleural fluid tap was cloudy and analysis showed WBC count 1086 cells/micro L (40% lymphocytes, 11% PMN, 27% monocytes, 22% mesothelial cells), negative acid-fast bacteria stain, pH 7.48, protein 1.7 g/dL, glucose 125 mg/dL, LDH 75 units/L and negative culture. Later during the hospital course, patient complained of headache and brain MRI was done. Findings were small acute infarct in the left posterior cerebellar hemisphere with some parenchymal enhancement concerning for an infectious etiology. Also, a probable subacute infarct in the right posterior corona radiata was reported and the vessels adjacent to the posterior sylvian fissure were suspicious for a possible mycotic aneurysm.
Upon admission to our facility, we initiated empiric antimicrobial therapy for presumptive diagnosis of culture negative endocarditis. He was placed empirically on intravenous (IV) ceftriaxone 2 g daily, oral (PO) doxycycline 100 mg daily, PO rifampin 600 mg daily and IV gentamicin 5 mg/kg daily to cover fastidious organisms, Coxiella, Rickettsia, Mycoplasma, Brucella and Bartonella. Bartonella species was part of our differential diagnosis as the patient was originally from Democratic Republic of Congo. Bartonella species (mostly henselae and quintana) are among the most common causes of blood culture negative endocarditis in Africa, being responsible for 9.5%-28.4% of all cases. Pertinent laboratory results were as follows: negative mycobacterial and fungal blood cultures, negative Brucella and Coxiella serologies, negative HIV antibody, Rheumatoid factor 83 U/mL, Anti smooth antibody 1:640, negative coombs test, Rickettsia typhi IgM not detected and IgG >1:256, B. henselae IgM and IgG were indeterminate at first and the repeat sample in a week demonstrated B. henselae IgG >= 1:1024 by immunofluorescnece (IFA), B. henselae IgM < 1:20, B. quintana IgG >=1:1024), B. quintana IgM <1:20. Based on these positive serologies, ceftriaxone and rifampin were discontinued. Patient underwent aortic valve and mitral valve replacements. Subsequently, B. quintana DNA was detected from mitral valve by PCR amplification targeting the riboflavin synthase gene (ribC) and 16S rRNA gene. Cultures on chocolate agar turned positive for B. quintana after 21 days and B. quintana endocarditis diagnosis was confirmed. Post valve replacements, doxycycline was continued for total of six weeks and gentamicin was given for the first two weeks.