Eastern and Southern Africa, the region most affected by the HIV/AIDS epidemic, is making great strides to scale up access to prevention and treatment services, a United Nations official said today, adding that focus is on behavioural change and prevention of mother-to-child transmission. Of the estimated 34 million people living with HIV/AIDS across the world, almost three quarters live in Eastern and Southern Africa, Sheila Tlou, the Director of the Regional Support Team for the Joint UN Programme on HIV/AIDS (UNAIDS) told a media briefing in Geneva.