Since the mid-1980s, preventing HIV transmission among people who inject drugs (PWIDs) has been one of the cornerstones of the UK’s response to HIV. The early comprehensive implementation of harm reduction, particularly needle and syringe programmes, has been widely acknowledged as key to a low prevalence of HIV among PWIDs in the UK. However, this harm-reduction strategy was developed to avert an HIV epidemic among people injecting heroin and while the prevalence in this population remains low, it is clear that there are now emerging populations of PWIDs with different patterns of drug use and risks
