禽流感是一種由甲型流感病毒的一種亞型（也稱(chēng)禽流感病毒）引起的傳染性疾病，被國(guó)際獸疫局定為甲類(lèi)傳染病,。通常只感染鳥(niǎo)類(lèi),，很少情況會(huì)感染豬。禽流感病毒高度針對(duì)特定物種,，但在罕有情況下會(huì)跨越物種間障礙感染人,。自從1997年在香港發(fā)現(xiàn)人類(lèi)也會(huì)感染禽流感之后，此病引起全世界衛(wèi)生組織的高度關(guān)注,。其后,，本病一直在亞洲區(qū)零星爆發(fā)，但在2003年12月開(kāi)始,，禽流感在東亞多國(guó)──主要在越南、韓國(guó),、泰國(guó)──嚴(yán)重爆發(fā),，并造成越南多名病人喪生。直到2005年中,，該病不但未有平息的跡象,，而且還不斷擴(kuò)散，遠(yuǎn)至東歐多個(gè)國(guó)家,。
中國(guó)科學(xué)院動(dòng)物研究所何宏軒研究組通過(guò)對(duì)215個(gè)人源的H5N1病毒株和5885個(gè)禽源的H5N1病毒株的HA序列進(jìn)行分析,，并結(jié)合地理信息學(xué)數(shù)據(jù)和鳥(niǎo)類(lèi)遷徙動(dòng)態(tài)數(shù)據(jù)，綜合分析認(rèn)為：（1）全球人源H5N1病毒株分為4個(gè)大分支,，即Southern China cluster（華南分支,，CN）、Indonesia cluster（印度尼西亞分支,，ID）,、Indo-China cluster（印支分支，IC)以及Middle Asia-north Africa cluster（中亞-北非分支,，MN）,。進(jìn)一步的糖基化位點(diǎn)分析表明，這四大分支屬于3大病毒類(lèi)型,，即廣東196型或原始型（the GD196 type or original type）,，過(guò)渡性（the Transitional type）和印度尼西亞型（the Indonesia type）。這些結(jié)果表明,，全球人源H5N1病毒株根據(jù)地域不同存在不同的進(jìn)化亞型,，而且在防控上也要選用同地域毒株制備疫苗。（2）在進(jìn)化分支上,，人源H5N1病毒株分散在禽源的H5N1病毒株中,，這表明人源H5N1病毒株來(lái)源于禽源H5N1病毒株，不同地域病毒傳播是通過(guò)鳥(niǎo)類(lèi)來(lái)傳播的，而人與人之間或人與鳥(niǎo)之間單項(xiàng)不能直接傳播,。（3）從病毒溯源上來(lái)看,，本研究的結(jié)果推測(cè)華南很可能多個(gè)病毒支系的共同來(lái)源。綜上所述,，我們了解到,，人感染H5N1禽流感病毒多是接觸了感染H5N1病毒的病禽而感染，從發(fā)生的人病例的事實(shí)來(lái)看,，符合這一說(shuō)法,。
該研究提出的對(duì)全球流感毒株的分型和分類(lèi)的方法尚屬首次，對(duì)于未來(lái)研究禽流感的進(jìn)化具有重要的參考價(jià)值,。（生物谷Bioon.com）
生物谷推薦英文摘要：
The Journal of Infectious Diseases 2010;202:452–458 doi: 10.1086/653709
New Evidence Suggests Southern China as a Common Source of Multiple Clusters of Highly Pathogenic H5N1 Avian Influenza Virus
Bin Wu,1,a Chengmin Wang,1,a Guoying Dong,1 Yunhai Guo,1 Dale Louis Nolte,4 Thomas Jude Deliberto,4 Jianguo Xu,3 Mingxing Duan,2 and Hongxuan He1
1National Research Center for Wildlife Borne Diseases, Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, and 2State Key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, Beijing, and 3Department of Respiratory, First Hospital, Jilin University, Changchun, China; 4National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, Colorado
Highly pathogenic H5N1 avian influenza is considered an avian disease, although there is some evidence of limited human‐ o‐human transmission of the virus. A global effort is underway to control or eradicate the highly pathogenic H5N1 avian influenza virus in poultry and prevent human exposure, both of which may also reduce the risk of pandemic emergence. Hemagglutinin gene sequences from 215 human H5N1 influenza viruses were used to trace the source and dispersal pattern of human H5N1 influenza viruses on a global scale. A mutation network and phylogenetic analyses of the hemagglutinin gene show that human H5N1 influenza viruses can be clearly divided among 4 clusters across geographic space. On the basis of analysis of the N‐glycosylation sites at positions 100 and 170 in the hemagglutinin protein, human H5N1 influenza viruses were also divided into 3 types. When we combined these analyses with geographic information system data analyses, we found that Southern China is often a common source of multiple clusters of H5N1 influenza viruses and that each cluster has different dispersal patterns and individual evolutionary features. In summary, the genetic evidence presented here provides clear evidence for multiple clusters of human H5N1 influenza viruses that initially originated in Southern China.
