Abstract

Zimbabwe has experienced one of the largest and most rapid declines in HIV prevalence in sub-Saharan Africa. This presentation will describe the range of evidence has been assembled and examined to distinguish the contribution of HIV prevention programmes to this decline from the effects of the natural dynamics of the epidemic, spontaneous responses to high AIDS mortality, and changes in socio-economic context. Some of the practical challenges, advantages and limitations of the different methods of evaluation used—observational studies, mathematical modelling, randomised trials—will be discussed.