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 < 0.001) and within networks of CRF07_BC (0.338), CRF01_AE (0.497), CRF55_01B (0.146) and subtype B (0.756) by transmission intensity matrices and assortativity coefficients. Multivariable exponential random graph models were further applied to assess associations of age mixing patterns with HIV-1 transmission links in the network, indicating that, compared with male-male pairs born in the 1980s , those born in the same decade—whether earlier (＜1960: aOR = 7.018, 95% CI: 5.733-8.590; 1960s: aOR = 2.297, 95% CI: 1.973-2.674; 1970s: aOR = 1.430, 95% CI: 1.309-1.563) or later (≥1990: aOR = 1.539, 95% CI: 1.430-1.656) were more likely to form a transmission link. These patterns were consistent across major HIV-1 genotypes. This molecular transmission network analysis revealed age-assortative mixing as a key driver of HIV-1 transmission in Guangzhou, highlighting the need for age-specific strategies to enhance HIV prevention efforts.

年龄混合模式对于理解HIV-1（人类免疫缺陷病毒1型）传播、制定针对性公共卫生干预措施至关重要，但在中国及其他疫情集中流行地区，相关研究仍较为匮乏。本研究收集了2008-2020年中国广州市8395例新诊断HIV感染者（People With HIV, PWH）的HIV-1 pol基因序列及社会人口学数据。研究人员按照感染者的出生年份对序列进行分组，并重建了HIV-1分子传播网络。在3636例感染者中共检测到11766条传播连接，其中主要连接集中于1970年代与1980年代出生的感染者（16.7%）、1980年代与1990年代出生的感染者（16.5%）、1980年代出生者之间（15.0%）以及1990年代出生者之间（11.5%）。通过传播强度矩阵及同配性系数（assortativity coefficient）分析，整体及CRF07_BC、CRF01_AE、CRF55_01B、B亚型传播网络中均观察到显著的年龄趋同混合模式（整体同配性系数=0.407，P<0.001；各网络分别为0.338、0.497、0.146、0.756）。研究进一步采用多变量指数随机图模型，评估网络中年龄混合模式与HIV-1传播连接的关联，结果显示：与1980年代出生的男男性行为配对相比，同十年出生的感染者配对——无论是更早出生组（＜1960年：调整后比值比（adjusted odds ratio, aOR）=7.018，95%置信区间（confidence interval, CI）：5.733~8.590；1960年代：aOR=2.297，95%CI：1.973~2.674；1970年代：aOR=1.430，95%CI：1.309~1.563）还是更晚出生组（≥1990年：aOR=1.539，95%CI：1.430~1.656）——均更易形成传播连接。上述模式在主要HIV-1基因型中均保持一致。本项分子传播网络分析表明，年龄趋同混合是广州市HIV-1传播的关键驱动因素，凸显了制定针对性年龄分层策略以强化艾滋病预防工作的必要性。