一大型HIV-1分子簇在某低流行县传播特征分析

  目的  研究四川省某获得性免疫缺陷综合征（acquired immune deficiency syndrome，AIDS，也称艾滋病）低流行县HIV-1分子簇的特征，为开展精准干预提供依据。  方法  对四川省某AIDS低流行县2011年1月-2019年3月新诊断的人类免疫缺陷病毒（human immunodeficiency virus，HIV）感染者/AIDS病人（HIV/AIDS）测定其感染HIV-1 pol基因区序列，进行分子簇分析，并对存活病例进行流行病学问卷调查。  结果  新诊断的113个HIV/AIDS中，有49.6%（56/113）属于同一分子簇（CRF01_AE4），该簇平均基因遗传距离为0.006 1，2011年发现首例，并呈持续快速增长的趋势（χ2_趋势=11.626，P=0.001）。簇内病例以中老年平均年龄（50.5±13.0）岁]、文盲或小学文化（42.9%）、已婚（67.9%）、男性（76.8%）为主，感染前鲜有外出史（17.0%），45.5%经异性商业性行为感染，性交易主要发生在本地（87.5%）、低档场所（55.0%），性交易从未坚持使用安全套。75.0%经异性商业性行为感染的簇内病例为2016年及之后诊断发现；1例在得知感染后仍保持高危性行为且拒绝抗病毒治疗，在分子传播簇中与多个病例有连接关系。  结论  一大型传播网络在某低流行县内持续快速扩张，本地低档场所性交易是导致该网络扩张的主要原因。

Study on the epidemiological characteristics of a large HIV-1 molecular cluster in a low epidemic county

  Objective  To study the characteristics of HIV-1 molecular clusters in a low-epidemic county in Sichuan Province, so as to provide a basis for precise intervention.  Methods  Research subjects included HIV/AIDS patients who were newly diagnosed from January 2011 to March 2019 in a low-epidemic county in Sichuan Province, of whom the HIV-1 pol gene was sequenced, and molecular cluster analysis was performed. Epidemiological questionnaire survey was conducted among survival cases.  Results  Among 113 newly diagnosed cases, 49.6% (56/113) belonged to the same molecular cluster (CRF01_AE4), and the average genetic distance of this cluster was 0.006 1. The first case was found in 2011 and there was a trend of continuous rapid growth (χ2_trend=11.626, P=0.001). The cases in the cluster were mainly seniors (average age was 50.5±13.0), low-educated (42.9%), married (67.9%), male (76.8%) and only few had a going-out history (17.0%). 45.5% were infected through heterosexual commercial sexual behaviors, and the sexual transactions mainly occurred in low-cost commercial sex venues (55.0%) in local areas (87.5%), and never consistently used condoms in the sex trade. 75.0% cases who were infected through heterosexual commercial sex were mainly diagnosed since 2016. One case, who continued having high-risk sexual behaviors after being informed and refused the anti-retroviral therapy, was found connecting with multiple cases in the molecular transmission cluster.  Conclusions  A large-scale transmission network had continued to expand rapidly in a HIV low-endemic county and sexual transactions in local low-cost commercial sex venues were the main reason for the network expansion.