HIV Infection in an Urban Social Network: a Progress Report

The completion of the second year of the Colorado Springs Study provided new insights into the location of HIV infection in a large urban social network. About 250 persons were interviewed by the end of the second year and provided information on over 3500 reported social relationships. Roughly 2000 persons were found to be part of a core connected region which included six individuals confirmed HIV positive. The density of social ties in this core region was about 0.01. The average number of steps (along shortest paths) between HIVinfected persons and others in connected core of this large urban social network was quite small (between 4 and 6). Some implications of the observations are discussed. When individuals are connected together to form large social networks, the concepts and methods of network analysis can lead to a better understanding of factors affecting the spread of infectious agents transmitted in the course of close or intimate personal contact. A better understanding of the factors involved, in turn, can lead to more effective disease control strategies (Klovdahl, 1985).