Sexually transmitted disease and human immunodeficiency virus. Is everyone at risk and does everyone have to pay?

The pattern of disease within populations depends on the complex interaction between individuals. For example, the linking of individuals to form social and sexual networks affects disease incidence and prevalence. As described by Potterat, the formation of these networks results in various patterns of disease spread. However, phenomena that occur among individuals do not necessarily mirror those observed in groups or populations. The interactions that characterize the relationship between individual and group level phenomena were considered during this session of the Tenth International Meeting of the International Society for STD Research. By examining these interactions we hoped to address the following two questions: Are all individuals equally at risk for sexually transmitted diseases (STD) and infection with human immunodeficiency virus (HIV)? and Must the costs and benefits of interventions designed to prevent these outcomes be divided equally among all individuals to ensure the success of such interventions?