Centre de Recherche de Tour du Valat, Arles, France.
PLoS One. 2012;7(8):e43974. doi: 10.1371/journal.pone.0043974. Epub 2012 Aug 27.
During the last decade, the role of wildlife in emerging pathogen transmission to domestic animals has often been pointed out. Conversely, far less attention has been paid to pathogen transmission from domestic animals to wildlife. Here, we focus on the case of game restocking, which implies the release of millions of animals worldwide each year. We conducted a 2-year study in the Camargue (Southern France) to investigate the influence of hand-reared Mallard releases on avian influenza virus dynamics in surrounding wildlife. We sampled Mallards (cloacal swabs) from several game duck facilities in 2009 and 2010 before their release. A very high (99%) infection rate caused by an H10N7 strain was detected in the game bird facility we sampled in 2009. We did not detect this strain in shot ducks we sampled, neither during the 2008/2009 nor the 2009/2010 hunting seasons. In 2010 infection rates ranged from 0 to 24% in hand-reared ducks. The 2009 H10N7 strain was fully sequenced. It results from multiple reassortment events between Eurasian low pathogenic strains. Interestingly, H10N7 strains had previously caused human infections in Egypt and Australia. The H10 and N7 segments we sequenced were clearly distinct from the Australian ones but they belonged to the same large cluster as the Egyptian ones. We did not observe any mutation linked to increased virulence, transmission to mammals, or antiviral resistance in the H10N7 strain we identified. Our results indicate that the potential role of hand-reared Mallards in influenza virus epizootics must be taken into account given the likely risk of viral exchange between game bird facilities and wild habitats, owing to duck rearing conditions. Measures implemented to limit transmission from wildlife to domestic animals as well as measures to control transmission from domestic animals to wild ones need to be equally reinforced.
在过去的十年中，野生动物在新兴病原体向家畜传播中的作用经常被指出。相反，人们对病原体从家畜向野生动物传播的关注要少得多。在这里，我们关注的是游戏重新放养的情况，这意味着每年在全球范围内释放数百万只动物。我们在法国南部的卡马格（Camargue）进行了一项为期两年的研究，调查了人工饲养的野鸭释放对周围野生动物中流感病毒动态的影响。我们在 2009 年和 2010 年释放之前，从几个游戏鸭养殖场采集了野鸭（泄殖腔拭子）。在我们 2009 年采样的野鸟养殖场中，检测到了一种非常高（99%）的 H10N7 株感染率。我们在 2008/2009 和 2009/2010 狩猎季节期间，都没有在我们采样的猎鸭中检测到这种菌株。2010 年，人工饲养的鸭子的感染率从 0 到 24%不等。2009 年的 H10N7 株进行了全序列分析。它是由欧亚低致病性株之间的多次重排事件引起的。有趣的是，H10N7 株以前曾在埃及和澳大利亚引起人类感染。我们测序的 H10 和 N7 节段与澳大利亚的明显不同，但它们属于与埃及的相同大聚类。我们在鉴定的 H10N7 株中没有观察到任何与增加毒力、向哺乳动物传播或抗病毒耐药性相关的突变。我们的研究结果表明，鉴于鸭养殖条件下野鸟养殖场和野生栖息地之间病毒交换的可能性风险，必须考虑人工饲养的野鸭在流感病毒爆发中的潜在作用。需要同样加强实施的措施，以限制野生动物向家畜传播，以及控制家畜向野生动物传播。
