Endovascular infections caused by Histoplasma capsulatum: a case series and review of the literature.
BACKGROUND
Endovascular infection is an uncommon but devastating manifestation of histoplasmosis, which is often diagnosed late in disease.


OBJECTIVE
To evaluate the clinical and pathologic characteristics of patients with endovascular infections caused by Histoplasma capsulatum.


METHODS
All cases of patients with documented endovascular histoplasmosis at a single tertiary care center in an endemic region during the period 1993-2010 were reviewed.


RESULTS
Patients presented with a subacute febrile illness and a history of endovascular devices. All patients had positive Histoplasma serology. Routine bacterial culture results were negative for all patients. In addition to yeast forms typical of histoplasmosis, pathologic findings also revealed mycelial forms in 4 of 5 patients. Inflammation was scant. Urinary antigen detection was positive in 4 of 5 patients and Histoplasma blood culture results were positive for 3 of 5 patients. Four patients were treated with a combination of surgical and medical therapy, which consisted of amphotericin B followed by itraconazole; these 4 patients had complete resolution of symptoms and no documented relapse. One patient died before planned surgery.


CONCLUSIONS
Histoplasma capsulatum endovascular infections are clinically characterized by a subacute febrile illness with negative bacterial cultures in patients with prosthetic endografts or valves. Noninvasive diagnostics are often the initial clue to the diagnosis. Combined medical and surgical treatment is associated with survival. On histopathologic examination both mycelial and yeast forms are often observed, with absent to minimal tissue inflammatory reaction.
Department of Infectious Diseases, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USA. ledtkec@ccf.org
Christopher
C
Ledtke
Susan J
SJ
Rehm
Thomas G
TG
Fraser
Nabin K
NK
Shrestha
Carmela D
CD
Tan
E Rene
ER
Rodriguez
J Walton
JW
Tomford
Anil
A
Jain
Bruce
B
Lytle
Douglas
D
Johnston
Joseph
J
Sabik
Steven M
SM
Gordon
David
D
van Duin
D000328:Adult; D000368:Aged; D000666:Amphotericin B / Q000627:therapeutic use*; D000935:Antifungal Agents / Q000627:therapeutic use*; D004696:Endocarditis / Q000382:microbiology*; D057510:Endovascular Procedures / Q000009:adverse effects; D005260:Female; D006658:Histoplasma; D006660:Histoplasmosis / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D017964:Itraconazole / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged
D000935:Antifungal Agents; D017964:Itraconazole; D000666:Amphotericin B