Opening the case: HIV/AIDS in Botswana and the problem of adherence In 2009, almost 25 per cent of all adults in Botswana carried the HI virus. In recent years, HIV prevalence overall has been levelling off at around 17 per cent, and surveillance data show that HIV infections among young people under 25 years of age have been declining consistently (UNAIDS/NACA 2010; UNAIDS/WHO 2010). In the wake of the pandemic, however, mortality has increased and average life expectancy has decreased dramatically – in Botswana from approximately 70 years in 1990 to its lowest value of 36 years in 2004 (life expectancy at birth; UNAIDS 2006). Together with Swaziland, Botswana ranks highest in HIV prevalence of all countries worldwide (see Figure 8.1). After the introduction of a nationwide therapy scheme, the average life expectancy rose again considerably and is currently at c.54 years (UNDP 2009).