AIDS in rural Africa: a paradigm for HIV-1 prevention.

Networks of concurrent sexual partnerships may be the primary cause of epidemic spread of HIV-1 in parts of sub-Saharan Africa. This pattern of sexual behaviour increases the likelihood that individuals experiencing primary HIV-1 infection transmit the virus to other persons. Networks of concurrent partnerships are likely to be important in both the early ('epidemic') and late ('endemic') phases of HIV-1 transmission. Interventions should aim to break the sexual networks, whatever the stage of the epidemic. However, prevention of transmission in the endemic phase also requires a greater awareness of early clinical manifestations of HIV-1 infection in the general population. Such awareness, coupled with the availability of condoms and access to HIV-1 testing facilities, may reduce transmission in discordant couples.