Imperial College London - Department of Infectious Disease Epidemiology, University of York - Centre for Health Economics, University College London - Institute for Global Health, University College London - Institute for Global Health, University College London - UCL Centre for Advanced Research, Ministry of Health (Malawi), University College London, University College London, University College London, University of Malawi - College of Medicine, Imperial College London, Ministry of Health (Malawi), Kamuzu University of Health Sciences, Imperial College London, University College London, University of York, University College London - Institute for Global Health, Kamuzu University of Health Sciences and Imperial College London - MRC Centre for Global Infectious Disease Analysis