Objective: To analysis the status of HIV infection and the related factors among students of men who have sex with men (MSM) from voluntary counseling and testing (VCT) clinics in Changzhoucity Jiangsu province. Methods: A total of 236 subjects with previous male sexual history, 16-25 years of age and less than 3 months of confirmation time of HIV positive infection were recruited in Changzhou from January 2014 to December 2017. Questionnaires were conducted and plasma samples were collected for selenium and HIV antibody testing. The relevant factors of HIV infection among MSM were screened by classification tree model. The model was evaluated using cross validation and receiver operating characteristic (ROC) curve. Results: The age of subjects was (20.76±1.97) years old. The age of the first sex with men was (19.14±1.85) years old and the plasma selenium content was (82.59±11.99) ng/ml. Of the 236 subjects, 74.58% (176 cases) were college students or undergraduates; 8.90% (21 cases) were diagnosed with venereal diseases in the last year; 80.93% (191 cases) received health services in the last year, and the positive rate of HIV antibody was 25.00% (59 cases). Four relevant factors were screened by the classification tree model, including the diagnosis of sexual transmitted diseases (STDs) in the last year, health services in the last year, plasma selenium level and education level. The most important factor was whether STDs were diagnosed in the last year. The estimate of re-substitution and cross-validation of the classification tree model was 0.186 and 0.195, and the standard error was 0.025 and 0.026, respectively. The area under the ROC was 0.706 (P<0.001). Conclusion: The MSM HIV antibody positive rate of VCT students in Changzhou City, Jiangsu Province was 25.0%. The diagnosis of STDs in the last year, receiving health services in the last year, plasma selenium level and education level were relevant factors of HIV infection.
目的： 分析江苏省常州市各自愿咨询检测（VCT）门诊学生男男性行为者（MSM）HIV感染状况及相关因素。 方法： 于2014年1月至2017年12月，在常州市各VCT门诊招募既往有过男男性行为史、年龄为16~25岁、HIV阳性感染者的确证时间≤3个月的在校学生MSM，共纳入236例研究对象。开展问卷调查并采集静脉血，检测血浆硒和HIV抗体。采用分类回归树模型筛选学生MSM感染艾滋病的相关因素，采用交叉验证法和受试者工作特征曲线进行模型评价。 结果： 研究对象年龄为（20.76±1.97）岁，首次发生同性性行为的年龄为（19.14±1.85）岁，血浆硒含量为（82.59±11.99）ng/ml；文化程度为大专或本科者占74.58%（176例），最近1年诊断性病者占8.90%（21例），最近1年接受健康服务者占80.93%（191例），HIV抗体阳性率为25.0%（59例）。分类树回归模型筛选出4个相关因素，分别为最近1年诊断性病、最近1年接受健康服务、血浆硒水平和文化程度，其中最近1年是否诊断性病为最主要的相关因素。分类回归树重替代估计量与交叉验证估计量分别为0.186和0.195，标准误差分别为0.025和0.026；利用预测值绘制的受试者工作特征曲线下面积为0.706（P<0.001）。 结论： 江苏省常州市VCT学生MSM HIV抗体阳性率为25.0%，最近1年诊断性病、最近1年接受健康服务、血浆硒水平和文化程度是艾滋病感染的相关因素。.
Keywords: Classification tree model; Cross-sectional studies; HIV; Homosexuality, male; Students.