Introduction
The 2010 global report on the AIDS epidemic (UNAIDS, 2010) paints a positive picture of the current situation globally and in Africa. Though levels of infections are still high, the epidemic showed signs of stabilization or decline since the 1990s, including in sub—Saharan Africa where the epidemic has been at the centre of public health concerns for more than thirty years. In 2009 22.5 million children and adults were living with HIV in the region, representing 68% of the global total of 33.3 million. Among people aged 15-49 years the prevalence rate was 5.9% in 2001 and 5% in 2009 in sub-Saharan Africa, and less than 1% in both years globally, In terms of rates of infection the worst hit countries have been in east and southern Africa (e.g., Kenya and Uganda, South Africa, but even with a lower infection rate Nigeria in West Africa has one of the largest number of people living with AIDS because of its large population.
The decline in AIDS cases in Africa is due to better targeting of risk factors through prevention efforts and the scaling up of antiretroviral therapy in many countries. However, AIDS remains one of the health and development challenges in sub-Saharan Africa today and the search for ways to sustain or accelerate the reported decline in infection rates must continue. This search needs to include greater attention to the role of risky behaviours associated with substance use and dependence, including injection drug use (which has been reported in a growing number of-countries) and harmful consumption of alcohol (a widespread problem across the region).