The Social Geography of Partner Selection in Toronto, Canada: A Qualitative Description of "Convection Mixing".

The geographic distribution of sexually transmitted infections reflects the underlying social process of sexual partner selection. This qualitative study explored the social geography of partner selection among sexual minority men and used the results to develop a mid-range theory of STI transmission. In-depth interviews with 31 sexual minority men who lived, worked, or socialized in Toronto, Canada, occurred in June and July 2016. Participants were asked how they found sexual partners and reconstructed their egocentric sexual networks for the previous 3 months. Participants described an iterative process of partner selection involving intention (sex versus dating), connecting with community, and selecting a partner based on intersecting partner characteristics (external, internal, and emergent feelings when interacting with potential partners) and personal preferences. Geography influenced partner selection three ways: (1) participant search patterns maximized the number of potential partners in the shortest distance possible; (2) the density of sexual minority men in a participant's community directly impacted participant's social and sexual isolations; and (3) geosexual isolation influenced sexual mixing patterns. Participants described "convection mixing," where assortative urban mixing nested within disassortative suburban mixing resulted in movement from the suburbs to downtown and back to the suburbs. We theorize that convection mixing may be contributing to the persistence of STI epidemics in core and outbreak areas by creating STI reservoirs outside of, and connected to, core and outbreak areas.