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海南省艾滋病分子流行病学研究

Molecular Epidemiology on HIV in Hainan Province

【作者】 邓巍

【导师】 秦川; 卢葳; 李万波; 张连峰;

【作者基本信息】 中国协和医科大学 , 病理学与病理生理学, 2008, 博士

【摘要】 自从艾滋病传入我国以来在我国的传播速度日益增长,范围越来越广。西南边疆是我国艾滋病流行最早的地区,也是我国艾滋病检测的重点地区,但与其邻近的海南岛的流行特点尚没有被大家所认识。为了研究海南省HIV-1流行的病原学以及传播特征,我们于2007年3月抽样采集了一批HIV-1感染者及部分感染者配偶的血样本,对这些样本进行了病原学与免疫学的检测和分子流行病学的分析。自1990年以来,海南省CDC在全岛开展了近五十万人份的HIV血清学调查,迄今共检出HIV感染者五百余人(检出率约为0.1%)。我们在全省主要疫情的市县进行抽样调查,共采集96份血样本,经检测其中88份为HIV-1感染样本。免疫学指标显示CD4~+细胞计数平均值士标准差为(303±230)细胞/μl,血浆HIV-1病毒载量几何平均值±标准误为(37810±40958)copies/ml,二者呈负相关关系(r~2=0.27,P<0.001)。HIV-1感染者同时感染了乙型或丙型肝炎病毒的人分别占61%和69%。在分子流行病分析方面,我们扩增出83名HIV-1阳性的感染者体内病毒的POL及ENV基因片段,结果显示海南省艾滋病流行状况有以下几个特点:1.总体上低流行,特定人群和局部地区高流行的态势。2.HIV-1人群的感染方式主要为两种,一是通过静脉吸毒,占主要地位(64%),主要分布在儋州、乐东、东方、三亚等沿海地区,病毒亚型以CRF01_AE重组亚型占绝对优势(100%);二是异性性传播(33%),散在分布,亚型分布呈多样化,包括CRF01_AE、B、B’、C和CRF08_BC。3.海南省最主要的病毒亚型为CRF01_AE重组亚型,主要在静脉吸毒者及其性伴侣之间传播,形成了一个庞大的传播群。其次为B’亚型(9.6%),此外还有C亚型(2.4%)、B亚型(1.2%)、CRF08_BC(1.2%)以及1例CRF01_AE/B’重组亚型。4.根据最大似然法(ML)的计算结果(bootstrap值是在重复了1000次的基础上得到的),以bootstrap values>98%,average branch lengths<0.015为判断标准,在83个HIV-1感染者中,有66人(79.5%)分属于4个大小不同的传播群,传播群1最大,有59人,传播群2有3个人,传播群3和4各有2个人。我们对83个扩增出的POL基因片段作了耐药性突变的分析,结果显示所有人均未发现与蛋白酶抑制剂相关的主突变,但均有次突变。部分次突变位点在B(B’)亚型病毒与CRF01_AE重组亚型之间存在明显差异:M36I(0%vs 100%,p<0.01),L63P(100%vS 23%,p<0.01),A71T(44%vs 1%,p<0.01),V77I(89%vs 1%,p<0.01)。在有关逆转录酶抑制剂的突变方面,进行抗病毒治疗人群中20%发现了主突变。主突变位点为:D67N、K70N、F116Y、Q151M、M184V、K101E/H/N/Q、V106L、Y181C、和G190A。总的来看,海南省艾滋病疫情虽然仍处于低流行状况,但已进入增长期。由于存在庞大的传播群尤其是我国仍有近80%的病原携带者尚未检出(潜在庞大的传染原),如不及时实施有效的干预,极易造成艾滋病的扩散流行。因此要把握艾滋病从高危人群向一般人群传播的关键时期,加强针对各类高危人群的干预工作,加大宣传力度。同时要扩大监测范围和人群类别,及早采取相应的对策,遏止艾滋病的进一步传播蔓延。

【Abstract】 To investigate the genetic background of HIV-1 strains in Hainan Province of South China we performed an HIV serological study and molecular epidemiological study based on blood samples of volunteers collected in March,2007.Of 96 volunteers, accounting for 18%of total Hainan samples,88 were confirmed to be infected with HIV-1.The peripheral blood CD4 T cell counts(mean±SD,3034±230 cells/μl) have inverse correlation to the plasma viral loads(geometric mean±SE,37,810±40,958 RNA copies/ml,P<0.001).61%and 69%of total 88 persons were infected with HBV or HCV respectively.83 pol and env sequences were successfully amplified respectively. Phylogenetic analysis was conducted for each new sequenceindividually.The result is asfollow:1.Low prevalence of HIV was detected in Haina Province.But high morbidity was detected in special crowd in some area.2.As many as 64%of HIV-1-infected persons were injecting drug users(IDUs).Most of them live in west and south littoral. All IDUs with AIDS are infected with subtype CRF01AE HIV.33%(29/88) of HIV-1-infected cases acquired the virus by heterosexual transmission.Subtype CRF01AE,B,B’,C,CRF08BC was infected by heterosexual transmission.3.The most important subtype is CRF01AE.Transmission of CRF01AE by both heterosexual contacts and IDU formed a huge transmission cluster.We also identified other subtype including B’(9.6%),C(2.4%),B(1.2%),CRF08BC(1.2%) and a new recombination of CRF01AE/B’.4.The existence of transmission clusters was determined using the statistical robustness of the ML topologies assessed by high bootstrap values(>98%) with 1000 resamplings and short branch lengths(genetic distances<0.015%) of HIV-1 pol gene sequences.Of the 83 pol sequences analysis,66(80%) segregated into 4 clusters having sequence similarity based on the established criteria.Cluster 1 has 59 persons forming a big one.To understand the prevalence and distribution of HIV-1 drug resistant genotypes,we conducted a study on the 83 persons infected with HIV.Although primary protease resistance mutations were not found in all 83 persons,secondary mutations are found in each person.The frequencies of protease secondary mutations were found to be significantly different between subtype B and CRF01AE strains:M36I(0%vs 100%, p<0.01 ),L63P(100%vs 23%,p<0.01),A71T(44%vs 1%,p<0.01),V77I(89%vs I%,p<0.01 ).Of the 83 persons,10(12%) have already received antiretroviral therapy (ART).As for the reverse transcriptase,20%(2/10) of 10 person with ART have primary resistance mutations,i.e.D67N,K70N,F116Y,Q151M,M184V,K101E/H/N/Q,V106L, Y181C,G190A.Taken together,our finding shows that injecting drug transmission is becoming a major risk for current HIV outbreaks in Hainan province.Given that nearly 80%of people with HIV-1 infection are undiagnosed in China,the very large number of undiagnosed persons with advanced(high viremia) HIV-1 infection may represent a major source leading to new nationwide HIV outbreaks.Multisectoral responses are needed and more needs to be done to increase understanding and support from revevant agencies.An enhanced HIV/AIDS education is urgently needed to reduce the stigma.Our findings demonstrated that some drug resistant HIV-1 strains have been emerging overtime since the initiation of antiretroviral therapy.And the resistance strains might have transmitted in a group of people.Since there are only limited drug regimens available to patients in China,the antiretroviral therapy management should be strengthened.

  • 【分类号】R512.91
  • 【下载频次】205
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