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

Abstract

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.

PIP: In Africa, the heterosexual spread of HIV-1 may be caused by the high proportion of men and women with more than one regular sexual partner. The primary agent for the spread of the epidemic may have been truck drivers with regular and casual partners at their official and unofficial stops. It is possible that one truck driver could infect every one of his partners on one transcontinental trip. These partners would then infect local men and transmit the virus throughout the countryside, with a declining prevalence occurring at each stage. Most of the female partners of truck drivers are single, but most of the other male partners of these women are married. Transmission risk is enhanced in the presence of sexually transmitted diseases (STDs), the incidence of which is also increased by sexual networks. This wave of transmission will saturate the sexual networks and will then move into a relatively noninfectious asymptomatic phase and cause "stable" seroconversion in the rural communities. This will be followed by a wave of deaths among traders, then businessmen, then country people. Thus, interventions to break or partially break the sexual networks are a priority at all stages of the epidemic. Young people must be dissuaded from having sex with older people or with people who have had sex with older partners. Equal-age partnerships could also improve women's status. Ways to break the sexual networks include intervening in the settings where such liaisons occur, especially in the roadside settlements, and maybe in revitalizing marriage. It may also be necessary to promote awareness of the early clinical signs of HIV-1 infection among the population. Controlling STDs may only delay the transmission of HIV in discordant couples, but this, along with the most important changes in sexual behavior and reductions in the sexual networks, provides the most hope for rural Africa.