我国部分地区H1亚型禽流感病毒分子流行病学分析

Epidemiological Surveys of H1 Subtype Avian Influenza Viruses in China during 2011—2013

[目的 ]国内外对于H1亚型禽流感病毒缺乏系统的流行病学调查,对其流行状况和风险知之甚少。本研究旨在通过根据流行病学调查,分析该病毒流行状况和风险。[方法 ]2011–2013年间,在中国系统地开展了7次H1亚型禽流感病毒流行病学调查,共从24省(自治区、直辖市)949个场点采集38435份禽拭子样品,进行病毒分离、RT-PCR、序列测定等。[结果 ]共检出H1亚型禽流感病毒12株(5株H1N2、3株H1N3和4株H1N8),样品总阳性率为0.03%,鸡、鸽、鸭、鹅样品阳性率分别为0.00%(0/28786)、0.00%(0/646)、0.19%(11/5793)和0.06%(1/1131)。基因序列表明,这些病毒均属于东半球分支,均为低致病性禽流感病毒,且仅结合禽型受体。[结论 ]中国H1亚型禽流感病毒在家禽中感染率较低,主要分布在水禽中,未发现易于结合人型受体的突变,提示H1亚型禽流感病毒对中国家禽和公共卫生威胁较小。

[Objective] H1 subtype avian influenza viruses （AIVs） have been seldom investigated, and their circula- tion and risk remain unknown. In the study, epidemiological surveys were conducted to analyze the circulation and risk of the viruses. [Methods] Seven systematical surveys of H1 subtype AIVs in China in 2011-2013 were conducted, with the collection of 38435 swab samples from 949 sites in 24 provinces （autonomous regions and municipalities） . The samples were detected by means of virus isolation, RT-PCR and sequencing. [Results] A total of 12 H1 subtype AIVs （5 H1N2, 3 H1N3 and 4 H1N8） were detected from the swab samples with the general prevalence of 0.03%. The virus prevalence in chicken, duck, goose and pigeon samples were 0.00% （0/28786） , 0.00% （0/646） , 0.19% （ 11/5793 ） and 0.06% （ 1/1131 ） . These 12 viruses all belonged to the viral Eastern-Hemisphere clade, and were all low pathogenic without any mutations associated with increased binding to human-like receptors. [Conclusion] These data suggested that H1 subtype AIVs mainly circulated in waterfowls and were of low prevalence in the poultry in China, and they were of low risk to the poultry and public health.