June 6, 2011
HIV/STD risk "is determined in part by sexual network characteristics, which include spatial parameters," the authors wrote. Geography and proximity of partner selection may explain neighborhood-level differences in morbidity for these conditions. The study of the effects of neighborhood factors on HIV/STD transmission in high-density urban areas, therefore, must include an understanding of the geography of partner selection.
Adults reporting one or more heterosexual partnerships were surveyed at the Baltimore site of the National HIV Behavioral Surveillance system. Spatial assortativity was defined as both partners living in the same or adjacent census tracts and was based on participant report. Locations identified as HIV core areas were those census tracts in the top quartile for standardized HIV/AIDS case rates.
A total of 307 participants provided data on 776 recent sexual partnerships. Geographic data were obtained for 510 partnerships (66 percent). Forty-seven percent reported choosing spatially assortative partners. After adjusting for partnership type, gender, and number of partners, individuals living in areas with a high prevalence of HIV were more likely to choose spatially assortative partners compared to residents of lower prevalence areas. "Although this population exhibited assortative mixing in all types of partnerships, racial and age assortatives were not associated with choosing spatially assortative partners," the researchers found.
"Over 15 years ago, STD clinic patients in Baltimore were found to seek partners with close proximity. We confirm these results in a non-STD clinic population, indicating a continuing need for neighborhood approaches to intervention programs in urban areas," the authors concluded.