1. Bristol Medical School, Population Health Sciences; University of Bristol; Bristol UK
2. Faculty of Public Health and Policy; London School of Hygiene and Tropical Medicine; London UK
3. Public Health England; UK
4. Public Health Institute, Liverpool John Moores University; Liverpool UK
5. Kirby Institute for Infection and Immunity, UNSW; Australia
6. Health and Life Sciences; Glasgow Caledonian University; UK
7. Blood-borne Viruses and Sexually Transmitted Infections Section; Health Protection Scotland; UK
8. Substance Misuse - Drugs and Alcohol; Public Health Wales; UK
9. School of Media, Society and Culture; University of West of Scotland; UK
10. Department of Medicine; University of California, San Diego; USA
11. Bristol Drugs Project; UK
12. School of Medicine; University of Dundee; UK