[A clustered epidemic investigation of non-marital non-commercial heterosexual contact of HIV in Zhejiang Province].

Objective: To identify the transmission relationship between HIV infection cases the non-marital non-commercial heterosexual contact in Zhejiang Province. Methods: When HIV positive was informed during January 2020 to January 2022, the staff conducted an epidemiological investigation to collect cases information on sociodemographic characteristics, mobility information, past HIV testing history, high-risk sexual behaviors, sexual partners, and etcetera. At the same time, 6-8 ml of blood from the new diagnosis of people infected with HIV before antiviral treatment was collected to separate the bleeding plasma. pol gene was amplified by nucleic acid extraction and PCR, sequenced by Sequencer 5.0 software, and Cytoscape 3.6.0 software was used to draw HIV molecular transmission network. Results: From January 2020 to January 2022, 88 HIV infected individuals were found in Pujiang County, of which 74 were transmitted through heterosexual transmission, of which 31 were infected through non-marital non-commercial heterosexual contact. Preliminary case studies have found that three female cases have engaged in unprotected non-marital non-commercial heterosexual contact with one male case. Among the 4 infected individuals, 2 of their spouses tested positive for HIV antibodies. Molecular transmission network monitoring was carried out on 65 newly diagnosed cases of heterosexual transmission with acquired sequences, forming 9 transmission clusters. The largest cluster contained 10 cases. A total of 11 HIV-infected individuals were involved in this HIV cluster epidemic. They were 3 males and 8 females, all over 50 years old and were farmers or rural housewives. They were traced to 7 sexual partners (6 negatives of HIV, 1 undetected). Among the 18 respondents' sexual social network relationships, there were 6 couples, 8 permanent partners, and 3 temporary partners. Among 11 HIV infected individuals, there were 9 cases of non-marital non-commercial heterosexual transmission and 2 cases of intramarital transmission. The epidemiological association between 7 non-married non-commercial heterosexual partners and case 2 (56-year-old male farmer), 3 cases confirmed by epidemiological investigation and molecular transmission cluster results, 3 cases confirmed by molecular transmission cluster and epidemiological investigation results, and 1 case confirmed by epidemiological investigation results. Conclusions: The transmission mode of this cluster epidemic was to spread HIV through heterosexual sex with a male case as the core, then cause the transmission within marriage and between fixed sexual partners. The combination of epidemiological investigation and molecular transmission network traceability survey supports the conclusion of this study.目的： 明确浙江省一起非婚非商业异性性行为传播模式HIV感染者之间的传播关系。 方法： 对2020年1月至2022年1月浙江省浦江县新确证的疑似非婚非商业异性性传播HIV聚集性疫情相关HIV感染者及其性伴开展流行病学调查（流调），收集社会人口学特征、流动信息、HIV既往检测史、高危性行为史及性伴侣情况等信息。结合HIV分子传播网络监测进行传播关系分析，采集新确证HIV感染者在抗病毒治疗前的全血样本6~8 ml，分离出血浆。通过核酸提取、PCR扩增pol基因，通过Sequencher 5.0软件拼接整理测序结果，使用Cytoscape 3.6.0软件构建HIV分子传播网络进行分析。 结果： 2020年1月至2022年1月，浦江县共发现HIV感染者88例，其中异性性传播74例，有31例为非婚非商业性行为感染。初步个案调查发现，其中3例女性均与1例男性发生过无保护的非婚非商业异性性行为。4例感染者中，有2例的配偶HIV抗体检测阳性。对新确证感染者开展分子传播网络分析，共获得异性性传播序列65例，形成9个传播簇，最大传播簇中包含10例HIV感染者。HIV聚集性疫情共涉及HIV感染者11例，男性3例，女性8例；年龄均≥50岁，职业类型为农民或农村家庭妇女；追踪溯源到7例性伴，其中6例HIV阴性，1例未检测。18例调查对象的性社会网络关系中，夫妻关系6对，固定性伴关系8对，临时性伴关系3对。11例HIV感染者中，非婚非商业异性性传播9例，婚内传播2例。7例非婚非商业异性性伴与病例2（56岁男性农民）的流行病学关联，3例有流调和分子传播簇结果证实，3例有分子传播簇和流调结果证实，另有1例流调结果证实。 结论： 本起HIV聚集性疫情的传播模式是以病例2为核心，通过非婚非商业异性性行为传播HIV，继而引起婚内和固定性伴间的传播。流调与分子传播网络相结合的溯源调查支持本结论。.