基于CD4^＋T淋巴细胞水平反推法估计云南省德宏傣族景颇族自治州HIV诊断发现率

Estimation of HIV diagnosis rate with CD4^＋ T-lymphocyte level and infected-time model in Dehong Prefecture, Yunnan Province

目的 估计云南省德宏傣族景颇族自治州（德宏州）HIV感染者的总例数，推算德宏州HIV的诊断发现率。方法 通过艾滋病综合防治信息系统收集德宏州2006—2015年度新诊断报告的HIV感染者的相关信息进行分析，主要包括年龄、性别、感染途径、CD4＋T淋巴细胞数值和诊断时间等。首先采用各年度诊断报告感染者的首次CD4＋T淋巴细胞计数反推其感染发生的年份及分布情况；然后依据贝叶斯理论估计每个年度的诊断发现比例；从而估计出每个年度的应新发感染总例数，累计加和得到该地区各年度应感染总例数；最终应用诊断报告感染者例数除以推算出的应感染总例数得到该地区的HIV诊断发现率。结果 2006—2015年，德宏州诊断报告感染者共8 215例，其中2007年最多，为1 297例（15.8%），2015年最少，为361例（4.4%）。贝叶斯理论分析结果显示，2005年及以前和2006—2015年各年度HIV诊断发现比例分别为88%、75%、71%、68%、66%、61%、58%、53%、45%、40%和33%，2005年及以前应新发感染者为11 197例，2006—2015各年应新发感染人数分别为653、671、723、640、509、468、369、375、285和224例。最终推算截止到2015年底，德宏州HIV感染者总例数为16 114例，HIV诊断发现率为87.7%。结论 2006—2015年德宏州HIV诊断发现率处于较高水平。自2008年起，云南省德宏州的每年新发感染者例数呈下降趋势。

Objective To estimate the total number of people infected with HIV and to calculate the diagnosis rate of HIV in Dehong Prefecture, Yunnan Province.Methods Through the comprehensive AIDS prevention and treatment information system, we collected and analyzed the relevant information of the new diagnosis report of HIV in Dehong Prefecture, Yunnan Province in 2006-2015, mainly including age, sex, infected transmission, CD4＋ T-lymphocyte counts, diagnostic time and so on. The content of the study was to establish a model method for estimating the diagnosis rate of HIV in Dehong. First, used the first CD4＋ T-lymphocyte count after HIV diagnosis to estimate the date of infection. Then based on the estimated time from HIV infection to diagnosis we can estimate the diagnosis delay distribution which in turn can be used to account for individuals infected but not yet diagnosed and thus estimated the total number of HIV infections （diagnosed and undiagnosed）. Finally, the number of new infections in each year was added to estimate the total number of infected people, and the number of people who had been diagnosed was divided by the total number of infected persons to obtain the proportion of HIV diagnosis rate.Results There were 8 215 reported cases in Dehong from 2006 to 2015, of which 1 297 cases were reported in 2007 （15. 8%） and 361 cases （4.4%） in 2015. The diagnosis rate of newly infected persons were 88% in 2005 and before. And from 2006 to 2015, the diagnosis rate of newly infected persons were 75%, 71%, 68%, 66%, 61%, 58%, 53%, 45%, 40% and 33%, respectively. The total number of newly infected persons in 2005 and before was 11 197 cases. The annual new infected number from 2006 to 2015 was 653, 671, 723, 640, 509, 468, 369, 375, 285 and 224 cases. The total number of people infected with HIV in Dehong was 16 114 cases, and the diagnosis rate was 87.7%.Conclusion The diagnosis rate of HIV in Dehong was at a high level. Since 2008, the annual number of new infections in Dehong has been declining.