Concurrent partnerships could cause AIDS epidemics.

There is a need for new hypotheses to supplement existing explanations for the observed differences in HIV prevalence between countries and within countries. Due to high levels of viraemia during the initial phase of HIV infection, networks of concurrent regular partnerships in a community could be the determining factor in the development of an AIDS epidemic. If this hypothesis is true, projections of the future development of the epidemic could be altered. Simple health education messages based on the hypothesis might make a major contribution to the prevention and control of AIDS epidemics.