Along it are full service establishments with food, beer, bed, and a woman. For years they have been continually exposed to HIV, yet they remain free of any trace of the virus. Tests reveal no antibodies or the viral organism. They appear to have specialized cells that can kill off the virus before it can inflict any damage. Urbanization and its resulting erosion of traditional sex taboos and lifestyles may be the key to the emergence of HIV in Africa.
Urban centers are an ecosystem than can amplify infectious contagious diseases.
AIDS in Africa did not spread simply because the virus was present. The change in the interaction between the agent, the host and the environment is usually required for the epidemic. Social change, including the effects urbanization and population movements contribute movements contribute to the rapid spread of the AIDS virus. One study has shown that in one remote area, the number of people infected has remained low over the last ten years. It took an urban environment and all that goes with it to allow the HIV epidemic to explode.