HIV case finding and genetic transmission networks among MSM in Tijuana, Mexico

描述(由申请人提供)：该项目的目标是比较两种方法(伴侣接触者追踪[PCT]和基于地点的[VB]招募)在墨西哥提华纳男男性行为者(MSM)中识别以前未诊断的HIV+病例的有效性。我们还将使用自我报告的性网络、基于高危场所的网络和病毒遗传网络(通过分析病毒POL序列推断)来确认性传播网络中缺失的连接(例如，匿名性伴侣)。在我们的MSM试点数据中，HIV流行率为20.2%，其中88%的人不知道他们的HIV+血清状态。确定以前未确诊的艾滋病毒阳性者，并将他们联系在一起并将他们留在护理中，是治疗级联过程中的关键步骤，特别是在墨西哥的男男性接触者中，他们受到艾滋病毒的影响不成比例。目前还没有公开发表的研究将病例发现方法与基因分型相结合来推断性传播网络。将实现三个创新目标：目标1.比较PCT和高危场所(例如性俱乐部)的筛查参与者在提华纳男男性接触者中发现以前未诊断的HIV+病例的有效性。目的2.在基线和一年的随访中，确定通过PCT和VB产生的性接触网络(通过高危场所MSM从属关系的数据产生)映射到病毒遗传网络的程度。目的3.检查PCT和VB病例发现方法及其与(A)与HIV护理的联系和保留及其心理社会和环境决定因素之间的关系；以及(B)在一年的随访中评估性接触网络的稳定性。我们将比较这两种病例发现方法(n=200/组)在确定以前未诊断的MSM(主要结果)方面的生产力(即未诊断病例与筛查男性数量的比率)。通过将这些网络创建形式与艾滋病毒Poll序列数据进行比较，我们的目标是确定传播链(S)中存在的差距，从而增加我们对本地传播网络结构的理解。纵向数据将使我们能够检验性网络的稳定性，以及联系和保留护理的障碍和促进者。这是第一项研究：1)使用最先进的网络分析，确定病例查找方法在高危、研究不足的人群中识别以前未诊断的艾滋病毒+病例的有效性；2)使用多种形式的网络创建来确认性接触网络中缺失的联系；以及3)在严重缺乏这一信息的低收入到中等收入国家，确定与艾滋病毒/男男性行为者之间的联系和保留护理有关的因素。

DESCRIPTION (provided by applicant): The goal of this project is to compare the effectiveness of two methods (partner contact tracing [PCT] versus venue-based [VB] recruitment) for identifying previously undiagnosed HIV+ cases among men who have sex with men (MSM) in Tijuana, Mexico. We will also use self-reported sexual networks, high-risk venue-based networks, and viral genetic networks (inferred by analysis of viral pol sequences) to identify missing connections (e.g., anonymous partners) in sexual transmission networks. In our MSM pilot data, HIV prevalence was 20.2%, and 88% of those were unaware of their HIV+ serostatus. Identifying previously undiagnosed HIV+ persons and linking and retaining them in care are critical steps in the treatment cascade, particularly among MSM in Mexico, who are disproportionately affected by HIV. No published studies have examined case finding methods in combination with genotyping to infer sexual transmission networks. Three innovative aims will be addressed: Aim 1. Compare the effectiveness of PCT versus screening attendees of high-risk venues (e.g., sex clubs) as methods for finding previously undiagnosed HIV+ cases among MSM in Tijuana. Aim 2. Determine the extent to which sexual contact networks generated through PCT versus VB sexual networks (generated through data on MSMs' affiliations in high-risk venues) map onto viral genetic networks at baseline and one-year follow-up. Aim 3. Examine PCT versus VB case finding methods and their relationships to (a) linkage to and retention in HIV care and their psychosocial and environmental determinants; and (b) stability of sexual contact networks assessed over one-year follow-up. We will compare the productivity (i.e., ratio of undiagnosed cases to number of men screened) of these two case finding methods (n=200/group) in identifying previously undiagnosed MSM (primary outcome). By comparing these forms of network creation to HIV pol sequence data, we aim to identify where gaps exist in the chain(s) of transmission and thereby increase our understanding of the structure of local transmission networks. Longitudinal data will allow us to examine stability of sexual networks, as well as barriers and facilitators of linkage to and retention in care. This is the first study t: 1) determine the effectiveness of case finding methods to identify previously undiagnosed HIV+ cases in a high-risk, understudied population, using state-of-the-art network analyses; 2) use multiple forms of network creation to identify missing connections in sexual contact networks; and 3) identify factors associated with linkage and retention in care among HIV+ MSM in a lower- to middle-income country where this information is severely lacking.