Worldwide, HIV incidence (the number of new cases occurring in a given period, usually one calendar year) has stabilised and deaths have been declining in recent years (UN, 2010). However, the impact on the global burden of HIV-related disease is still huge.
Global HIV incidence stabilised at around 2.7 million new HIV infections annually between 2007 and 2010 (the most recent year for which data are available at the time of writing). AIDS-related deaths fell from 2 million in 2008 to 1.8 million in 2010 due to the expansion of access to effective antiretroviral therapy. One outcome of this success is that HIV prevalence (the number of people living with HIV infection) is steadily increasing – to 34 million in 2010. Just over 2 million of those people were children under 15 years infected via mother-to-child transmission (WHO, UNAIDS and UNICEF, 2011).
People with HIV are primarily in LMICs, but richer parts of the world are also affected. For example, according to the Health Protection Agency, 91 500 people in the UK were estimated to be living with HIV at the end of 2010, of whom 6660 were newly diagnosed in that year and around 24% were unaware of their infection status (HPA, 2011a).