Endemic Fungal Infective Endocarditis Caused by Coccidioides, Blastomyces and Histoplasma Species in the United States

Abstract

We describe a recent case of Coccidioides bioprosthetic aortic valve infective endocarditis successfully managed at our institution. This led us to perform a literature review of endemic fungal infective endocarditis in the United States caused by Coccidioides, Blastomyces, and Histoplasma. Symptoms preceded infective endocarditis diagnosis by several months. Patients with Coccidioides and Blastomyces infective endocarditis were younger with fewer comorbid conditions. Valvular involvement was relatively uncommon in Blastomyces infective endocarditis (27%). Fungemia was noted in patients with infective endocarditis due to Histoplasma (30%) and Coccidioides (18%). Mortality rates for infective endocarditis were high (Histoplasma, 46%; Coccidioides, 58%; Blastomyces, 80%); infective endocarditis was commonly diagnosed post-mortem (Coccidioides, 58%; Blastomyces, 89%). Most surviving patients with infective endocarditis (Histoplasma, 79%; Coccidioides, 80%) underwent valve surgery along with prolonged antifungal therapy. The two surviving patients with Blastomyces infective endocarditis received antifungal therapy without surgery.

Keywords: blastomyces; blastomycosis; coccidioides; coccidioidomycosis; endemic infections; endocarditis; fungal infection; histoplasma; histoplasmosis; valvular heart disease.

Figure 1. MRI brain without IV contrast showing a new area of right frontal subarachnoid hemorrhage (axial T2 image, arrow). Multiple additional foci of restricted diffusion reflecting embolic infarcts were noted in other cuts.

Figure 2. MRI brain without IV contrast with new right cerebellar infarct (axial T2 image, arrow).

Figure 3. Intra-operative view of infected metallic aortic valve with vegetations along sewing ring (arrow).