A strategic approach to identifying and combating porcine reproductive and respiratory syndrome virus outbreaks and other porcine viral diseases

该项目旨在开发一种战略方法，以识别和抗击菲律宾的猪繁殖与呼吸综合征病毒(PRRSV)暴发和其他猪病毒性疾病。菲律宾是世界第八大猪肉生产国，每年生产1700多万吨猪肉。然而，猪肉生产仍然在很大程度上依赖于后院养殖场，据报道，2016年，中国大约1,250万头动物中，有6%是后院养殖场的养殖场。后院农场和商业农场之间的这种耕作做法的差异需要一种强有力的战略方法，以防止病原体在农场和系统之间传播。后院养殖场经常使用杂交的商业西方和本土品种的猪，几乎没有生物安全措施，很少依赖兽医咨询，缺乏诊断，并允许相当自由和无监督地获得抗生素。相比之下，商业养殖场依赖于商业高度繁殖的西方猪品种，主要是从领先的饲养公司，如PIC和Topigs Norsvim等引进的长白/大白/杜洛克杂交猪。尽管商业农场很少使用诊断方法来支持临床诊断，但它们正在采用广泛的疫苗接种计划；然而，目前这在预防疾病方面并不总是有效的。改进对当前生物安全和疫苗接种战略的诊断、监测、监测和审查，对于采用有针对性的方法控制疾病至关重要。因此，该项目旨在评估商业农场和后院农场的当前健康状况，确定当前的疫苗接种战略，并确定PRRSV和PEDV的流行毒株和亚型。我们将使用传统的Sanger和新一代野外样本测序来进行系统动力学和系统地理分析，这将有助于了解PRRSV和PEDV疫情的传播和来源，并将进一步帮助制定疾病预防策略。研究结果将使我们对菲律宾养猪业目前的健康和生物安全状况有一个概述，并使我们能够开发具体、易于使用的诊断工具，使农民能够具体识别他们的猪群中存在的疾病，并为有针对性的疫苗接种和生物安全措施提供建议。我们的目标是开发基于逆转录环介导等温扩增(RT-LAMP)或逆转录重组酶聚合酶扩增(RT-RPA)的鉴别诊断工具，用于PRRSV、CSFV、PCV2和IAV-S等系统性病毒疾病以及PEDV、TGEV和轮状病毒等肠道病毒疾病的鉴别诊断。我们将使用简单易用的流条检测方法来开发多重测试，以区分病毒和/或亚型。根据我们的结果，我们的目标是为商业和后院养殖场提供有针对性的建议，以预防和抗击猪的病毒性疾病。

This project aims to develop a strategic approach to identify and combat porcine reproductive and respiratory syndrome virus (PRRSV) outbreaks and other porcine viral diseases in the Philippines. The Philippines are the world's 8th largest producer of pork producing over 1,700 mega tons of pork meat per year. However, the pork production still relies largely on backyard farms, which, in 2016, were reported to house 64% of the roughly 12.5 million animals in the country. This divergence in farming practises between backyard and commercial farms requires a robust strategic approach to prevent pathogen spread across farms and systems. The backyard farms often use crossbred commercial western/indigenous breed pigs, with few biosafety measures in place, rarely rely on veterinary consultation, lack diagnostics, and allow fairly liberal and unsupervised access to antibiotics. In contrast, the commercial farms rely on commercial highly bred western pig breeds, mostly Landrace/Large White/Duroc crosses brought in from leading breeding companies, such as PIC and Topigs Norsvim, amongst others. The commercial farms, despite little usage of diagnostics to support clinical diagnoses, are employing extensive vaccination schemes; however, currently this isn't always effective in preventing disease. Improved diagnostics, monitoring, surveillance and reviewing of current biosafety and vaccination strategies are essential to employ a targeted approach to disease control. Therefore, this project aims to assess the current health situation in commercial and backyard farms, to identify current vaccination strategies, and to identify circulating strains and subtypes of PRRSV and PEDV. We will use traditional Sanger and next generation sequencing of field samples to conduct phylodynamic and phylogeographic analysis, which will help to inform the spread and source of PRRSV and PEDV outbreaks, and which will further aid disease prevention strategies. The outcomes will give us an overview of the current health and biosafety situation in the Filipino pig industry and will allow us to develop specific, easy-to-use diagnostic tools that will enable farmers to specifically identify diseases present in their stock and advise targeted vaccination and biosafety measures. We aim to develop differential diagnostic tools based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) or reverse transcription recombinase polymerase amplification (RT-RPA) for systemic viral diseases including PRRSV, CSFV, PCV2, and IAV-S, and for enteric viral diseases including PEDV, TGEV, and rotaviruses. We will employ easy-to-use flow strip detection methods to develop multiplex tests that allow differentiation between viruses and/or subtypes. From our results, we aim to generate targeted advice for both commercial and backyard farms in order to prevent and combat viral diseases in pigs.