深圳市肾综合征出血热患者汉坦病毒基因特征研究

Genetic characteristics of hantavirus detected from HFRS patients in Shenzhen City

目的 研究深圳市引起肾综合征出血热（HFRS）的汉坦病毒主要型别及分子特征,为该市汉坦病毒的防制提供依据.方法 收集各医院送检HFRS患者急性期血清标本,提取血清中病毒RNA作为模板,采用逆转录-套式PCR扩增汉坦病毒基因组M片段G2区基因并进行序列测定,对汉坦病毒进行基因分型和同源性分析.结果 深圳市HFRS病例男性多于女性,患者发病年龄主要集中在20-60岁,其中20-49岁病例数最多,共发病242例,占发病总数的85.82％.从282例标本中用HTN型特异性引物扩增阳性4例,占1.42％;用SEO型特异性引物扩增阳性50例,占17.73％;总阳性率为19.15％.序列比较分析发现,深圳地区流行的SEO型汉坦病毒核苷酸序列的差异相对较小,其基因的离散度为0％-4.9％.从种系发生树看这些病毒分布在一个分支上,均为S2亚型.HTN型汉坦病毒的变异率较高,其基因的离散度为6.7％-21.0％,二例为H7亚型,二例为H9亚型,均为深圳市首次报道.结论 不同年份引起深圳地区HFRS的汉坦病毒仍以SEO型为主,且病毒变异较小,稳定性较高.首次发现HTN型病例存在.结合流行病学调查资料,证实HTN病例均为输入性病例.

Objective To study the genotype and characteristic of hantavirus prevailing in Shenzhen and to provide theoretical basis for controlling hemorrhagic fever with renal syndrome （HFRS）.Methods We collected serum specimens from patients at acute stage.Viral RNA was extracted from the sera.The G2 fragments of M segment from hantavirus was amplified with nested RT-PCR by using the Hantavirus genotype specific primers.The amplified genes were then sequenced,and subjected to genotyping and homology analysis with other known hantaviruses.Results In a total of 282 cases of epidemic hemorrhagic fever with renal syndrome in Shenzhen city from 2003 to 2014,the incidence rate in males was higher than that in females.Most of patients were 20-60 years old,and 242 cases were in 20-49 years old age group,which accounted for 85.82% of the total cases.Of all the 282 sera from patients at acute stage,four cases were positive by HTN specific primer（1.42%）,fifty cases were confirmed as SEO genotype（17.73%）,total positive rate was 19.15%.In general,SEO genotype was a prevalent type of hantavirus in Shenzhen.The variation of the nucleotide sequences among SEO viruses （nucleotide sequence divergence ranged 0%-4.9%）was lower than that among HTN genotype （nucleotide sequence divergence ranged 6.7%-21.0%）.The homology analysis of the nucleotides of G2 fragment showed that difference in nucleotide sequences among SEO viruses was very small,and phylogenic tree indicated hantaviruses in Shenzhen were in one branch along with BjFT01 、Beijing-Rn、Guang199 and HN71-L,belonging to S2 subtype.Two case of H7 HTN subtypes and two cases of HTN H9 subtype were first reported in Shenzhen.Conclusions The major genotype of hantavirus causing HFRS in Shenzhen is SEO genotype and the viruses were highly conserved.The existence of HTN cases were discovered for the first time.Combined with epidemiology information,it is suggested that four case can be classified as imported cases.