"The overall prevalence of HIV seen amongst people who inject drugs (PWID) in 2011 was similar to that seen in recent years, and remains higher than that found in the late 1990s. The Unlinked Anonymous Monitoring (UAM)138 survey of current and former PWID in England and Wales indicated an overall HIV prevalence of 1.3% in 2011 (ST09). In 2011, the prevalence was 1.4% amongst men and 0.95% amongst women, with prevalence increasing with age from 0.89% amongst those aged under 25 years to 1.4% amongst those aged 35 years and over (ST09)
"The prevalence of HIV amongst the PWID taking part in the 2011 UAM Survey across England, Wales and Northern Ireland was 1.2%.139 Between 2001 and 2011, prevalence varied between 0.93% and 1.6% (HPA 2012a; HPA 2012b; Figure 6.1).
"In 2011 in England, prevalence was 1.3%140, which is not significantly higher than in 2001 when the prevalence was 1.0%. In Wales in 2011, prevalence was 1.1%141 and in Northern Ireland prevalence was 0.56%142 (HPA 2012b).
"There is also evidence of on-going HIV transmission amongst PWID within the UK. In particular, the HIV prevalence amongst recent initiates to injecting in England, Wales and Northern Ireland (i.e. those who first injected during the preceding three years) has varied over time ranging from 0.36% in 2001 to 1.3% in 2008. The prevalence amongst the recent initiates participating in the UAM Survey in 2011 was 0.47%143 which is similar to the level found in 2001 (HPA 2012a; HPA 2012b; Figure 6.1)."

Source

UK Focal Point on Drugs, "United Kingdom Drug Situation 2012 Edition: Annual Report to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA)" (London, England: UK Government, Department of Health, October 31, 2012), p. 95.
http://www.emcdda.europa.eu/h…
http://www.emcdda.europa.eu/a…