An important component underlying the disparity in HIV risk between race/ethnic groups is the preferential transmission between individuals in the same group. We sought to quantify transmission between different race/ethnicity groups and measure racial assortativity in HIV transmission networks in major metropolitan areas in the United States. We reconstructed HIV molecular transmission networks from viral sequences collected as part of HIV surveillance in New York City, Los Angeles County, and Cook County, Illinois. We calculated assortativity (the tendency for individuals to link to others with similar characteristics) across the network for three candidate characteristics: transmission risk, age at diagnosis, and race/ethnicity. We then compared assortativity between race/ethnicity groups. Finally, for each race/ethnicity pair, we performed network permutations to test whether the number of links observed differed from that expected if individuals were sorting at random. Transmission networks in all three jurisdictions were more assortative by race/ethnicity than by transmission risk or age at diagnosis. Despite the different race/ethnicity proportions in each metropolitan area and lower proportions of clustering among African Americans than other race/ethnicities, African Americans were the group most likely to have transmission partners of the same race/ethnicity. This high level of assortativity should be considered in the design of HIV intervention and prevention strategies.

中文翻译：

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美国三大都市区艾滋病毒基因传播网络按种族/民族排序


种族/族裔群体之间艾滋病毒风险差异的一个重要组成部分是同一群体中个体之间的优先传播。我们试图量化不同种族/族裔群体之间的传播，并衡量美国主要大都市区艾滋病毒传播网络中的种族多样性。我们根据纽约市、洛杉矶县和伊利诺伊州库克县艾滋病毒监测收集的病毒序列重建了艾滋病毒分子传播网络。我们计算了整个网络中三个候选特征的分类性（个人与具有相似特征的其他人联系的倾向）：传播风险、诊断年龄和种族/民族。然后我们比较了种族/族裔群体之间的分类性。最后，对于每个种族/民族对，我们进行了网络排列，以测试观察到的链接数量是否与个体随机排序时预期的不同。所有三个司法管辖区的传播网络按种族/民族的分类比按传播风险或诊断时的年龄分类的要多。尽管每个大都市区的种族/族裔比例不同，且非裔美国人的聚集比例低于其他种族/族裔，但非裔美国人是最有可能拥有同一种族/族裔的传播伙伴的群体。在设计艾滋病毒干预和预防策略时应考虑这种高水平的分类性。