3636 clustered Guangzhou HIV-1 pol gene sequences (2008-2020)

Age mixing patterns are critical for understanding HIV-1 transmission and informing targeted public health interventions, yet they remain understudied in China and other concentrated-prevalence settings. HIV-1 pol gene sequences and sociodemographic data were collected from 8,395 people with HIV (PWH) newly diagnosed in Guangzhou, China (2008-2020). Sequences were grouped by birth year of PWH, and HIV-1 molecular transmission network were reconstructed. A total of 11,766 links were detected among 3636 PWH, primarily connecting PWH born in the 1970s and 1980s (16.7%), 1980s and 1990s (16.5%), 1980s and 1980s (15.0%), and 1990s and 1990s (11.5%). Significant age-assortative mixing patterns were observed overall (assortativity coefficient = 0.407, P