Transition and the HIV risk environment.

Transmission of HIV, like that of other behaviourally mediated infections, is influenced by the particular environments in which risk is produced. 2 The spread of HIV is shaped by variations in population behaviour and public health response, which are themselves shaped by differences in social, cultural, economic, and political condition. Prevention strategies aimed at individual behaviour may therefore only partially reduce the risk of transmission. We also need strategies to create the local environments and social structural conditions supportive of risk reduction by individuals and communities. Transition is a form of environmental change that can disrupt individual and community level risk reduction, weakening the capacity of public health responses. We suggest the concept of risk environment as a way of analysing the effect of large scale and abrupt social, economic, and political change in eastern Europe and the western Balkans on the spread of HIV and show how it can be used to plan a response.