Background

International and global organisations advocate targeting interventions to areas of high HIV prevalence (ie, hotspots). To better understand the potential benefits of geo-targeted control, we assessed the extent to which HIV hotspots along Lake Victoria sustain transmission in neighbouring populations in south-central Uganda.

Methods

We did a population-based survey in Rakai, Uganda, using data from the Rakai Community Cohort Study. The study surveyed all individuals aged 15–49 years in four high-prevalence Lake Victoria fishing communities and 36 neighbouring inland communities. Viral RNA was deep sequenced from participants infected with HIV who were antiretroviral therapy-naive during the observation period. Phylogenetic analysis was used to infer partial HIV transmission networks, including direction of transmission. Reconstructed networks were interpreted through data for current residence and migration history. HIV transmission flows within and between high-prevalence and low-prevalence areas were quantified adjusting for incomplete sampling of the population.

Findings

Between Aug 10, 2011, and Jan 30, 2015, data were collected for the Rakai Community Cohort Study. 25 882 individuals participated, including an estimated 75·7% of the lakeside population and 16·2% of the inland population in the Rakai region of Uganda. 5142 participants were HIV-positive (2703 [13·7%] in inland and 2439 [40·1%] in fishing communities). 3878 (75·4%) people who were HIV-positive did not report antiretroviral therapy use, of whom 2652 (68·4%) had virus deep-sequenced at sufficient quality for phylogenetic analysis. 446 transmission networks were reconstructed, including 293 linked pairs with inferred direction of transmission. Adjusting for incomplete sampling, an estimated 5·7% (95% credibility interval 4·4–7·3) of transmissions occurred within lakeside areas, 89·2% (86·0–91·8) within inland areas, 1·3% (0·6–2·6) from lakeside to inland areas, and 3·7% (2·3–5·8) from inland to lakeside areas.

Interpretation

Cross-community HIV transmissions between Lake Victoria hotspots and surrounding inland populations are infrequent and when they occur, virus more commonly flows into rather than out of hotspots. This result suggests that targeted interventions to these hotspots will not alone control the epidemic in inland populations, where most transmissions occur. Thus, geographical targeting of high prevalence areas might not be effective for broader epidemic control depending on underlying epidemic dynamics.

Funding

The Bill & Melinda Gates Foundation, the National Institute of Allergy and Infectious Diseases, the National Institute of Mental Health, the National Institute of Child Health and Development, the Division of Intramural Research of the National Institute for Allergy and Infectious Diseases, the World Bank, the Doris Duke Charitable Foundation, the Johns Hopkins University Center for AIDS Research, and the President's Emergency Plan for AIDS Relief through the Centers for Disease Control and Prevention.

中文翻译：

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量化艾滋病高发地区与周围社区之间的艾滋病毒传播流量：一项基于人口的乌干达拉凯研究。

背景

国际和全球组织主张将干预措施针对艾滋病毒高发地区（即热点地区）。为了更好地了解按目标控制的潜在好处，我们评估了维多利亚湖沿岸的HIV热点在乌干达中南部的邻近人群中维持传播的程度。

方法

我们使用来自拉凯社区队列研究的数据在乌干达拉凯进行了基于人口的调查。该研究调查了四个高发病率的维多利亚湖捕鱼社区和36个邻近的内陆社区中所有15-49岁的个体。在观察期内，从未接受过抗逆转录病毒治疗的HIV感染者中对病毒RNA进行深度测序。系统发育分析被用来推断HIV的部分传播网络，包括传播方向。通过数据解释了重建的网络，以了解当前的居住和迁移历史。对高流行区和低流行区之间以及之间的艾滋病毒传播流进行了定量调整，以对人口进行不完全抽样。

发现

在2011年8月10日至2015年1月30日之间，收集了有关Rakai社区同类研究的数据。乌干达拉凯地区共有25 882人参加，其中包括湖滨人口的75·7％和内陆人口的16·2％。5142名参与者为HIV阳性（内陆地区为2703 [13·7％]，捕鱼社区为2439 [40·1％]）。HIV阳性的3878人（75·4％）没有报告使用抗逆转录病毒疗法，其中2652人（68·4％）的病毒深度测序质量足以进行系统发育分析。重建了446个传输网络，包括293个具有推断传输方向的链接对。调整不完全采样后，在湖边地区估计发生了5·7％（95％可信区间4·4-7·3）的传播，在内陆地区发生了89·2％（86·0–91·8）的传播，

解释

维多利亚湖热点与周围内陆人口之间跨社区的HIV传播很少见，当它们发生时，病毒更常流入热点而不是从热点流出。该结果表明，针对这些热点地区的有针对性的干预措施不会单独控制大多数传播的内陆人口的流行。因此，根据潜在的流行病动态，将高流行地区的地理目标定位对于广泛的流行病控制可能无效。

资金

比尔和梅琳达·盖茨基金会，国家过敏和传染病研究所，国家心理健康研究所，国家儿童健康与发展研究所，国家过敏和传染病研究所内部研究处，世界银行，多里斯·杜克（Doris Duke）慈善基金会，约翰·霍普金斯大学（Johns Hopkins University）艾滋病研究中心以及总统通过疾病控制和预防中心进行的艾滋病救济紧急计划。