1 Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md. Electronic address: janitzio.guzman@nih.gov.
2 Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md; MedStar Georgetown University Hospital, Division of Infectious Disease and Tropical Medicine, Washington, DC.