McAuley A, et al. - Researchers analyzed four cross-sectional, anonymous, bio-behavioral surveys of almost 4,000 PWID attending services that offer injecting equipment across the Greater Glasgow and Clyde (GGC) between 2011 and 2018 to assess the impact of an outbreak of HIV among people who inject drugs (PWID) in GGC area of Scotland, on HIV prevalence trends in the population. In addition, they sought for individual and environmental risk factors linked with infection. The overall GGC sample was 3,641 PWID. Data revealed a rapid rise in prevalence of HIV among PWID population in Glasgow in spite of high coverage of harm reduction interventions. Homelessness, incarceration, and a major shift to injection of cocaine correlated with this increase. They emphasize robust surveillance through regular HIV testing of high-risk populations to ensure the detection of outbreaks and to inform rapid responses by the best available evidence.