1272. Acanthamoeba Infection After Biological Immunomodulator Therapy and Review of Successful Multi-Drug Treatment Regimens
Session: Poster Abstract Session: Travel/Tropical Medicine and Parasitology
Saturday, October 22, 2011
Room: Poster Hall B1
Background: Acanthamoeba is a free-living amoeba that rarely causes human infection and is usually described in patients with organ transplants or human immunodeficiency virus (HIV) infection.  Acanthamoeba infection in other populations is not well-described and the ideal treatment regimen remains undetermined. 

Methods: We report two cases of Acanthamoeba infection in patients with chronic lymphocytic leukemia after treatment with biological immunomodulators.  Both patients were treated with newer agents including rituximab and alemtuzumab and subsequently presented with necrotic skin ulcers.  Multiple skin biopsies were required before acanthamoebiasis was diagnosed.  Both patients were treated with aggressive multi-drug regimens but only one survived the infection. 

Results: We review the literature on Acanthamoeba infection reported in patients who were diagnosed antemortem with particular focus on successful treatment regimens.  Male sex, older age at presentation, and dissemination to the brain and/or other organs was associated with increased mortality.  Surprisingly, itraconazole, ketoconazole, and rifampin were associated with an improved rate of survival, while total number of drugs used as therapy was not significant.  

Conclusion: This report highlights the emergence of Acanthamoeba infection in patients treated with biological immunomodulator therapies and delivers new insights into successful treatment of this challenging disease.

Subject Category: T. Travel/tropical medicine and parasitology

Sagar A. Vaidya, MD, PhD1, Michelle Fox2, Dan Milner Jr., MD3, Sharon Roy, MD4, Govinda S. Visvesvara, PhD4, Nicolas Issa, MD3 and Francisco Marty, MD3, (1)Infectious Diseases, Massachusetts General Hospital, Boston, MA, (2)Harvard Medical School, Boston, MA, (3)Brigham and Women's Hospital, Boston, MA, (4)Center for Disease Control and Prevention, Atlanta, GA


S. A. Vaidya, None

M. Fox, None

D. Milner Jr., None

S. Roy, None

G. S. Visvesvara, None

N. Issa, None

F. Marty, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.