title: Histoplasma capsulatum endocarditis: multicenter case series with review of current diagnostic techniques and treatment.
abstract: Infective endocarditis is an uncommon manifestation of infection with Histoplasma capsulatum. The diagnosis is frequently missed, and outcomes historically have been poor. We present 14 cases of Histoplasma endocarditis seen in the last decade at medical centers throughout the United States. All patients were men, and 10 of the 14 had an infected prosthetic aortic valve. One patient had an infected left atrial myxoma. Symptoms were present a median of 7 weeks before the diagnosis was established. Blood cultures yielded H. capsulatum in only 6 (43%) patients. Histoplasma antigen was present in urine and/or serum in all but 3 of the patients and provided the first clue to the diagnosis of histoplasmosis for several patients. Antibody testing was positive for H. capsulatum in 6 of 8 patients in whom the test was performed. Eleven patients underwent surgery for valve replacement or myxoma removal. Large, friable vegetations were noted at surgery in most patients, confirming the preoperative transesophageal echocardiography findings. Histopathologic examination of valve tissue and the myxoma revealed granulomatous inflammation and large numbers of organisms in most specimens. Four of the excised valves and the atrial myxoma showed a mixture of both yeast and hyphal forms on histopathology. A lipid formulation of amphotericin B, administered for a median of 29 days, was the initial therapy in 11 of the 14 patients. This was followed by oral itraconazole therapy, in all but 2 patients. The length of itraconazole suppressive therapy ranged from 11 months to lifelong administration. Three patients (21%) died within 3 months of the date of diagnosis. All 3 deaths were in patients who had received either no or minimal (1 day and 1 week) amphotericin B.
authors.affiliation: University of Michigan Health System, Division of Infectious Diseases (JR, CAK), Ann Arbor, Michigan; Veterans Affairs Ann Arbor Healthcare System (CAK), Ann Arbor, Michigan; University of Wisconsin, Division of Infectious Diseases (JAS), Madison, Wisconsin; University of Kansas School of Medicine (MA), Wichita, Kansas; Sawtooth Infectious Diseases (SB), Boise, Idaho; Idaho Falls Infectious Diseases (MIB), Idaho Falls, Idaho; Stanford University, Division of Infectious Diseases and Geographic Medicine (SD), Palo Alto, California; Vanderbilt University, Division of Infectious Diseases (PWW), Nashville, Tennessee; University of Oklahoma College of Medicine, Division of Infectious Diseases (DAD), Oklahoma City, Oklahoma; Community Infectious Disease (SAN), Indianapolis, Indiana; Mayo Clinic, Division of Infectious Diseases (HRV), Phoenix, Arizona; North Dakota State University, Master of Public Health Program (PJC), Fargo, North Dakota; Mayo Clinic, Division of Infectious Diseases (PV), Rochester, Minnesota; Scott and White Clinic (JC), Texas A&M University College of Medicine, Temple, Texas; Infectious Diseases Specialists (SMS), Dallas, Texas; and MiraVista Diagnostics (LJW), Indianapolis, Indiana.
authors.forename: James
authors.initials: J
authors.lastname: Riddell
authors.forename: Carol A
authors.initials: CA
authors.lastname: Kauffman
authors.forename: Jeannina A
authors.initials: JA
authors.lastname: Smith
authors.forename: Maha
authors.initials: M
authors.lastname: Assi
authors.forename: Sky
authors.initials: S
authors.lastname: Blue
authors.forename: Martha I
authors.initials: MI
authors.lastname: Buitrago
authors.forename: Stan
authors.initials: S
authors.lastname: Deresinski
authors.forename: Patty W
authors.initials: PW
authors.lastname: Wright
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Drevets
authors.forename: Steven A
authors.initials: SA
authors.lastname: Norris
authors.forename: Holenarasipur R
authors.initials: HR
authors.lastname: Vikram
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Carson
authors.forename: Paschalis
authors.initials: P
authors.lastname: Vergidis
authors.forename: John
authors.initials: J
authors.lastname: Carpenter
authors.forename: Steven M
authors.initials: SM
authors.lastname: Seidenfeld
authors.forename: L Joseph
authors.initials: LJ
authors.lastname: Wheat
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000666:Amphotericin B / Q000008:administration & dosage*; D000935:Antifungal Agents / Q000008:administration & dosage; D000946:Antigens, Fungal / Q000097:blood / Q000652:urine; D001021:Aortic Valve / Q000473:pathology / Q000601:surgery; D017548:Echocardiography, Transesophageal / Q000379:methods; D004696:Endocarditis / Q000175:diagnosis / Q000209:etiology / Q000276:immunology / Q000628:therapy; D006325:Heart Atria / Q000473:pathology / Q000601:surgery; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000379:methods; D006658:Histoplasma / Q000187:drug effects / Q000276:immunology; D006660:Histoplasmosis / Q000150:complications / Q000175:diagnosis / Q000276:immunology / Q000628:therapy; D006801:Humans; D017964:Itraconazole / Q000008:administration & dosage*; D008297:Male; D008501:Medical Records, Problem-Oriented; D008875:Middle Aged; D009232:Myxoma / Q000150:complications / Q000473:pathology / Q000601:surgery; D016459:Prosthesis-Related Infections / Q000150:complications / Q000175:diagnosis / Q000382:microbiology / Q000628:therapy; D016896:Treatment Outcome; D014481:United States
chemical_list: D000935:Antifungal Agents; D000946:Antigens, Fungal; D017964:Itraconazole; D000666:Amphotericin B