But aren’t more heterosexual people diagnosed each year with HIV in the UK than gay men?
Health Protection Agency statistics show that there were 6,658 new HIV diagnoses in the UK in 2010. Just over 50 per cent (3,350) of these new diagnoses were among people who probably acquired HIV through heterosexual sex. However, of all of those heterosexual diagnoses, over 67 per cent were reported as being infected outside the UK, where a likely country of infection was reported.
In contrast, over 80 per cent of MSM who were diagnosed with HIV in 2009 probably acquired HIV within the UK. This means MSM account for around two thirds of UK sexually acquired HIV infections diagnosed in 2010, and new diagnoses amongst MSM in 2010 reached their highest level since the beginning of the epidemic. This makes MSM the group at by far the highest risk of new HIV infection in the UK today. Initial figures for 2011 show a continuing rise in MSM.
Although there are more heterosexual people living with HIV in the UK, the fact that the vast majority of them probably acquired HIV overseas has important implications for the way donated blood is screened for HIV. The best available evidence currently shows that heterosexual infection is statistically more likely to have taken place outside the UK, and that the majority of these people are not recently infected and are therefore outside the 'window period'. This means that their HIV infection will be more likely to show up using the current screening methods available to the National Blood Service. People who have had sex in high prevalence countries are already deferred.