21-ICRAD Virulent Non-Notifiable Avian Influenza; Determinants of virulence of emerging viruses

欧洲是世界上最大的禽肉和禽蛋生产国和禽类产品出口国之一。疾病暴发是家禽业的主要威胁。禽流感(AI)被列为最大的挑战，也是欧洲和世界家禽业的主要关切。在禽类中，禽流感病毒(AIV)株的严重程度被分为高致病性(HPAI)和低致病性(LPAI)。HPAI菌株会导致严重感染和高水平的死亡率。H5和H7类型的HPAI和LPAI是应呈报的疾病，即法律规定必须向政府当局报告的疾病。对信息的整理使当局能够监测疾病，并提供可能爆发的早期预警。欧洲成员国开展监测方案，涉及禽流感H5和H7亚型的疫情应向世界动物卫生组织通报。然而，不仅LPAI H5和H7以及HPAI亚型对家禽业构成威胁。一些非H5/H7亚型，如H3和H9，毒力很强，感染这些菌株也会造成严重的产量损失。除了经济后果外，这些毒力强的非应报告LPAI(nn-LPAI)亚型还会导致严重的临床症状、高死亡率和--在控制暴发的情况下--扑杀患病和/或健康的禽群，从而对动物福利产生重大影响。AI是一种人畜共患病，过去的流感大流行是由至少部分源自AI病毒的病毒引起的。因此，如果不能充分控制具有高人畜共患潜力的nn-LPAI，对公众健康的影响可能会很大。FluNuance财团的目标是开发一种诊断工具或鉴定系统，用于毒力强的nn-LPAI菌株。为了实现这一点，我们首先必须了解为什么这些通常低致病性的病毒会变得更具致病性，以及它们如何与宿主、鸡和野生动物的代表：野鸭、鹅和鸽子相互作用。这些知识将使我们能够更好地评估来自动物宿主的病毒给家禽养殖业带来的潜在风险，反之亦然。因此，家禽生产将较少受到这些病毒的威胁，从而减少对动物福利的负面影响，并减少被扑杀的鸡群数量。如果新出现的NN-LPAI具有很高的人畜共患病潜力，大流行的风险将会降低。因此，这项建议解决了家禽业日益增长的重要性，并符合消费者对“来自健康动物的健康食品”的需求。

Europe is one of the world's largest poultry meat and egg producers and exporter of poultry products. Disease outbreaks are a major threat for the poultry industry. Avian Influenza (AI) is listed as a top challenge and with that, is a major concern of the European and worldwide poultry industry. In poultry, the severity of AI virus (AIV) strains is classified into Highly Pathogenic (HPAI) or Low Pathogenic (LPAI). HPAI strains cause severe infections and high levels of mortality. HPAI and LPAI of the H5 and H7 types are notifiable diseases, i.e. diseases that are required by law to be reported to government authorities. The collation of information allows the authorities to monitor the disease, and provides early warning of possible outbreaks. European Member states conduct surveillance programmes and outbreaks involving AI H5 and H7 subtypes are notifiable to the OIE. However, not only LPAI H5 and H7 and HPAI subtypes form a threat for the poultry industry. Several of the non H5/H7 subtypes such as H3 and H9, can be very virulent and infections with these strains can also cause severe production losses. Besides the economic consequences, these virulent non-notifiable LPAI (nn-LPAI) subtypes have a major impact on animal welfare by causing severe clinical symptoms, high mortality rates and - in case of controlling the outbreak - culling of diseased and/or healthy flocks. AI is a zoonotic disease and past influenza pandemics were caused by viruses that were at least partly derived from AI viruses. Therefore, impacts on public health may be great if nn-LPAI with high zoonotic potential are not controlled adequately. The FluNuance consortium aims to develop a diagnostic tool or identification system for virulent nn-LPAI strains. To achieve this we will first have to understand why these normally low pathogenic viruses become more pathogenic and how they interact with their hosts, chickens and representatives of wildlife: mallard, geese and pigeon. This knowledge will allow us to better assess the potential risks that viruses from the animal reservoir imposes for the poultry industry and vice versa. As a consequence, poultry production will be threatened less by these viruses, thereby reducing negative impacts on animal welfare and decreasing the numbers of flocks that are culled. In case the emerging nn-LPAI has high zoonotic potential, the risk of a pandemic will be lowered. Thus, this proposal addresses the ever-increasing importance of the poultry industry and aligns with the consumers' demands for 'healthy food from healthy animals'.