1. Institute for Global Health, University College London, London, United Kingdom
2. Department of Health Services Research and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom
3. Medical Research Council Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
4. Medical Research Council/Chief Scientist Office, Social and Public Health Sciences Unit, University of Glasgow, Glasgow, United Kingdom
5. Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway