Are ducks contributing to the endemicity of highly pathogenic H5N1 influenza virus in Asia?
Are ducks contributing to the endemicity of highly pathogenic H5N1 influenza virus in Asia?
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DOI：
10.1128/jvi.79.17.11269-11279.2005
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发表时间：
2005-09-01
影响因子：
5.4
通讯作者：
Webster, RG
中科院分区：
文献类型：
--
作者：
Sturm-Ramirez, KM;Hulse-Post, DJ;Webster, RG
野生水禽是所有甲型流感病毒的天然宿主，这些病毒在这些鸟类中通常是非致病性的。然而，自2002年底以来，H5 N1在亚洲的爆发已导致休闲公园的水禽、家禽和野生候鸟死亡。流感病毒与其自然宿主之间的进化停滞可能已经被打破，这促使我们问水禽是否对H5 N1流感病毒疾病有抵抗力，以及它们是否仍然可以作为这些病毒的储存库。为了更好地了解鸭子中H5 N1病毒的生物学并试图回答这个问题，我们在2003年至2004年期间用23种不同的亚洲分离的H5 N1流感病毒接种青少年野鸭。所有病毒分离株在接种鸭体内均能有效复制，其中22株经易感接触者传播。病毒在气管内的复制水平高于泄殖腔，说明消化道不是H5 N1流感病毒在鸭体内复制的主要部位，粪-口途径可能不再是主要传播途径，病毒分离株的致病性从完全无致病性到高度致死性不等，且与气管病毒滴度呈正相关。然而，8个病毒分离株，是非致病性的鸭复制和传播有效的幼稚接触，这表明，高致病性H5 N1病毒引起的疾病的迹象最小的鸭子可以在亚洲的家鸭和野鸭，他们代表了一个严重的威胁，人类和兽医的公共卫生。
Wild waterfowl are the natural reservoir of all influenza A viruses, and these viruses are usually nonpathogenic in these birds. However, since late 2002, H5N1 outbreaks in Asia have resulted in mortality among waterfowl in recreational parks, domestic flocks, and wild migratory birds. The evolutionary stasis between influenza virus and its natural host may have been disrupted, prompting us to ask whether waterfowl are resistant to H5N1 influenza virus disease and whether they can still act as a reservoir for these viruses. To better understand the biology of H5N1 viruses in ducks and attempt to answer this question, we inoculated juvenile mallards with 23 different H5N1 influenza viruses isolated in Asia between 2003 and 2004. All virus isolates replicated efficiently in inoculated ducks, and 22 were transmitted to susceptible contacts. Viruses replicated to higher levels in the trachea than in the cloaca of both inoculated and contact birds, suggesting that the digestive tract is not the main site of H5N1 influenza virus replication in ducks and that the fecal-oral route may no longer be the main transmission path. The virus isolates' pathogenicities varied from completely nonpathogenic to highly lethal and were positively correlated with tracheal virus titers. Nevertheless, the eight virus isolates that were nonpathogenic in ducks replicated and transmitted efficiently to naive contacts, suggesting that highly pathogenic H5N1 viruses causing minimal signs of disease in ducks can propagate silently and efficiently among domestic and wild ducks in Asia and that they represent a serious threat to human and veterinary public health.