University College London, University of Newcastle, University of Malawi - Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi - Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Kamuzu University of Health Sciences, Kamuzu University of Health Sciences, Kamuzu University of Health Sciences, Kamuzu University of Health Sciences, University of Melbourne - Infection and Immunity, Government of the United Kingdom - Royal Free London NHS Foundation Trust, Wellcome Sanger Institute - Wellcome Genome Campus, University College London, University of Malawi - Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University College London, Wellcome Sanger Institute - Parasites and Microbes, Kamuzu University of Health Sciences, Kamuzu University of Health Sciences, Lions SightFirst Eye Hospital, University of Liverpool, University College London - NIHR Mucosal Pathogens Research Unit, University of Liverpool and University of Malawi - Malawi-Liverpool-Wellcome Trust Clinical Research Programme