University of Liverpool - Institute of Infection and Global Health, University College London - UCL Queen Square Institute of Neurology, University of Liverpool - Institute of Infection and Global Health, University of Liverpool - Institute of Infection and Global Health, University of Liverpool - Institute of Infection and Global Health, Encephalitis Society, Alder Hey Children's Hospital, Tropical and Infectious Diseases Unit, Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool, UK, Government of the United States of America - Division of High Consequence Pathogens and Pathology and University of Liverpool - Institute of Infection and Global Health