1 Department of Clinical Research, and Tuberculosis Modelling Group, Tuberculosis Centre, London School of Hygiene & Tropical Medicine, London, UK. katherine.horton@lshtm.ac.uk.
2 Tuberculosis Modelling Group, Tuberculosis Centre, and Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK.
3 Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.