浙江省嘉兴市2017年较大HIV分子传播簇病例流行病学特征分析

目的 分析2017年浙江省嘉兴市新发现的较大HIV分子传播簇和流行病学特征，筛选疑似高危传播者，为传染源管理及干预提供参考依据。方法 对2017年嘉兴市较大HIV分子传播簇所有HIV/AIDS病例采集血样，通过核酸提取、RT-PCR和巢式PCR法扩增pol基因，构建HIV分子传播网络，包括采用Sequencher 5.0软件拼接整理测序结果、BioEdit 7.2.0软件进行序列比对、Mega 6.0软件构建Neighbor-joining系统进化树、Cytoscape 3.6.0软件构建HIV分子传播网络图，形成若干个分子传播簇。对研究对象进行流行病学个案调查。采用EpiData 3.0和SPSS 20.0软件进行统计学分析。结果 2017年1-12月嘉兴市新报告HIV/AIDS病例210例，较大HIV分子传播簇为CRF07_BC亚型，传播簇共30例病例，个案调查26例，80.8%（21/26）为最近2年感染，30.8%（8/26）为最近1年感染。84.6%（22/26）为本市感染。5例疑似高危传播者均为同性性传播感染且≥ 45岁，其中3例有危险性行为时间较久、确诊前临时性伴数较多、MSM活动场所有危险性行为等高危行为特征。结论 2017年浙江省嘉兴市新发现的较大HIV分子传播簇最近2年在本市传播较快，传播和扩散风险较高。3例疑似高危传播者对该HIV分子传播簇的形成起到重要作用。

Epidemiological characteristics of molecular transmission cluster among reported HIV/AIDS cases in Jiaxing city, Zhejiang province, 2017

Objective To understand the epidemiological characteristics of one large HIV molecular transmission cluster in Jiaxing city, Zhejiang province, 2017 in order to select those people under high-risk and providing basis for programs on prevention. Methods During 2017, newly diagnosed HIV/AIDS cases in this city were recruited. Plasma samples were collected from subjects, followed by RNA extraction, RT-PCR and nest-PCR for pol gene amplification, before being sequenced and aligned. Mega 6.0 software was used to construct phylogenetic tree, and Cytoscape 3.6.0 software was used to identify HIV molecular transmission clusters. Cases within the large transmission clusters were investigated, using a field-epidemiology-questionnaire. Data related to socio-demographics and previous sexual behaviors were collected and EpiData 3.0 and SPSS 20.0 software were used. Results In the large transmission cluster with subtype identified as CRF07_BC, in Jiaxing, 2017, 26 cases of the total 30 cases were investigated. A total of 80.8% (21/26) could be identified as newly infected within the last two years and 30.8%(8/26) could be identified as newly infected within the last one year, including 22 cases infected locally. Among several infected cases who were at age 45 years or older, they admitted that they had experienced unprotected sexual contacts in local city for long time and having had more than 10 disclosed sexual contacts within the last two years at the local venues. Conclusions This molecular cluster had been formed and scaled up quickly in recent two years, it has played an important role in promoting and scaling up the HIV transmission. Three cases identificed as high risk played an importantrde role in scaling up this cluster.