1 Clinical Research Department, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK; Hospital for Tropical Diseases, University College London Hospitals, London, UK; UK Chagas Hub. Electronic address: Natalie.Elkheir@lshtm.ac.uk.
2 Clinical Research Department, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK; Hospital for Tropical Diseases, University College London Hospitals, London, UK; UK Chagas Hub.