Rothenberg Richard B, Dai Dajun, Adams Mary Anne, Heath John Wesley
From the *School of Public Health, and †Department of Geosciences, Georgia State University, Atlanta GA.
Sex Transm Dis. 2017 Feb;44(2):71-78. doi: 10.1097/OLQ.0000000000000561.
A study of network relationships, geographic contiguity, and risk behavior was designed to test the hypothesis that all 3 are required to maintain endemicity of human immunodeficiency virus (HIV) in at-risk urban communities. Specifically, a highly interactive network, close geographic proximity, and compound risk (multiple high-risk activities with multiple partners) would be required.
We enrolled 927 participants from two contiguous geographic areas in Atlanta, GA: a higher-risk area and lower-risk area, as measured by history of HIV reporting. We began by enrolling 30 "seeds" (15 in each area) who were comparable in their demographic and behavioral characteristics, and constructed 30 networks using a chain-link design. We assessed each individual's geographic range; measured the network characteristics of those in the higher and lower-risk areas; and measured compound risk as the presence of two or more (of 6) major risks for HIV.
Among participants in the higher-risk area, the frequency of compound risk was 15%, compared with 5% in the lower-risk area. Geographic cohesion in the higher-risk group was substantially higher than that in the lower-risk group, based on comparison of geographic distance and social distance, and on the extent of overlap of personal geographic range. The networks in the 2 areas were similar: both areas show highly interactive networks with similar degree distributions, and most measures of network attributes were virtually the same.
Our original hypothesis was supported in part. The higher and lower-risk groups differed appreciably with regard to risk and geographic cohesion, but were substantially the same with regard to network properties. These results suggest that a "minimum" network configuration may be required for maintenance of endemic transmission, but a particular prevalence level may be determined by factors related to risk, geography, and possibly other factors.
设计一项关于网络关系、地理相邻性和风险行为的研究，以检验以下假设：在处于风险中的城市社区中，这三者对于维持人类免疫缺陷病毒（HIV）的地方性流行都是必需的。具体而言，需要一个高度互动的网络、紧密的地理 proximity（此处原文可能有误，推测是“接近度”）以及复合风险（与多个性伴进行多种高危行为）。
我们从佐治亚州亚特兰大市两个相邻的地理区域招募了927名参与者：一个高危区域和一个低危区域，根据HIV报告历史来衡量。我们首先招募了30名“种子”（每个区域15名），他们在人口统计学和行为特征方面具有可比性，并使用链式设计构建了30个网络。我们评估了每个人的地理范围；测量了高危和低危区域人群的网络特征；并将复合风险测量为存在6种主要HIV风险中的两种或更多种。
在高危区域的参与者中，复合风险的频率为15%，而在低危区域为5%。基于地理距离和社会距离的比较以及个人地理范围的重叠程度，高危组的地理凝聚力显著高于低危组。两个区域的网络相似：两个区域都显示出具有相似度分布的高度互动网络，并且网络属性的大多数测量值实际上是相同的。
我们最初的假设得到了部分支持。高危组和低危组在风险和地理凝聚力方面存在明显差异，但在网络属性方面基本相同。这些结果表明，维持地方性传播可能需要一个“最小”的网络配置，但特定的流行水平可能由与风险、地理以及可能的其他因素相关的因素决定。
