1 Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA.
2 Helminth Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
3 Bill and Melinda Gates Foundation, Seattle, Washington, USA.
4 Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA. Electronic address: natha@ninds.nih.gov.