Traveling waves of HIV infection on a low dimensional 'socio-geographic' network

Observation of an essentially linear growth in time of U.S. and New York City AIDS cases, from about 1984 through early 1988, is shown to imply a relatively constant rate of transmission of HIV infection in its early stages, as has been observed for limited times in cohorts of male homosexuals in San Francisco and New York City. Observation by Potterat et al. of an exceptionally close intertwining of spatial and social patterns of endemic gonorrhea within a minority population, coupled with a percolation process model of HIV transmission within geographically constrained social networks, leads to inference that a constant rate of HIV transmission, in turn, implies a 'surface growth' phenomenon resulting in a traveling wave of infection advancing at a fixed 'velocity' along a 'one dimensional socio-geographic network.' Implications of this view are discussed for both data collection and analysis, and for intervention. Differences for the processes of disease transmission and control, based on the relative stability of socio-geographic networks, are postulated between the ghettoes of the middle-class male homosexual community and the physically devastated and socially distintegrated ghettoes of the minority urban poor.