Silva Gustavo S, Corbellini Luis G, Linhares Daniel L C, Baker Kimberlee L, Holtkamp Derald J
Veterinary Diagnostic and Production Animal Medicine Department, Iowa State University, Ames, IA, United States; Laboratory of Veterinary Epidemiology (Epilab), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Laboratory of Veterinary Epidemiology (Epilab), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Prev Vet Med. 2018 Nov 15;160:116-122. doi: 10.1016/j.prevetmed.2018.10.004. Epub 2018 Oct 10.
Biosecurity is defined as the set of practices carried out to prevent the introduction and spread of infectious agents in a herd. These practices are essential in swine production, especially for highly infectious agents such as porcine reproductive and respiratory syndrome virus (PRRSv). Even with years of research and experience over the last three decades, PRRSv is still causing productivity losses and is the major health problem affecting the global swine industry. Despite knowledge of the various ways in which the virus can be transmitted from one herd to another (e.g. animals, semen, truck, air, and people), determining the most frequent ways in which the virus is transmitted in the field is difficult. A systematic approach to assess vulnerabilities at a herd level related to PRRSv transmission could help producers prioritize biosecurity practices to reduce or avoid the occurrence of outbreaks. The aim of this study was to develop a biosecurity vulnerability score that represents the relative vulnerability of swine breeding herds to the introduction of PRRSv. To create the biosecurity vulnerability score (outcome), a multi-criteria decision analysis methodology was used to rank and quantify biosecurity practices based on expert opinion. To validate the biosecurity vulnerability score, a survey of biosecurity practices and PRRS outbreak histories in 125 breed-to-wean herds in the U.S. swine industry was used. Data on the frequency of PRRS outbreaks was used to test the hypothesis that biosecurity vulnerability scores were different between farms that have a low incidence of PRRS outbreaks, compared to farms that have a high incidence. In the two databases used, the scores consistently showed that farms with higher scores have a higher frequency of PRRS outbreaks. In the first validation, farms that had never had an outbreak investigation before had a significant (p < 0.02) lower score (0.29; 0.21-0.37) when compared to farms that had 2 or more outbreaks (0.43; 0.39-0.46). In the second, the farms of the control group also had significant (p < 0.004) lower scores (0.30; 0.27-0.33) compared to the case group (0.35; 0.33-0.38). Also, the results suggest that events related to swine movements, transmission by air and water, and people movements should be prioritized. The biosecurity vulnerability scores may be useful to assess vulnerabilities on biosecurity protocols in order to reduce the frequency of PRRS outbreaks and may help producers and veterinarians prioritize investments in improving biosecurity practices over time.
生物安全被定义为为防止感染因子在猪群中传入和传播而实施的一系列措施。这些措施在养猪生产中至关重要，特别是对于诸如猪繁殖与呼吸综合征病毒（PRRSv）等高度传染性病原体。尽管在过去三十年里进行了多年研究并积累了丰富经验，但PRRSv仍在造成生产损失，并且是影响全球养猪业的主要健康问题。尽管了解病毒可从一个猪群传播到另一个猪群的各种方式（例如动物、精液、卡车、空气和人员），但确定该病毒在实际生产中最常见的传播方式却很困难。一种系统的方法来评估猪群层面与PRRSv传播相关的脆弱性，有助于生产者确定生物安全措施的优先级，以减少或避免疫情爆发。本研究的目的是制定一个生物安全脆弱性评分，以代表种猪场对PRRSv传入的相对脆弱性。为了创建生物安全脆弱性评分（结果），采用了多标准决策分析方法，根据专家意见对生物安全措施进行排名和量化。为了验证生物安全脆弱性评分，对美国养猪业125个繁殖至断奶猪群的生物安全措施和PRRS疫情历史进行了调查。关于PRRS疫情发生频率的数据用于检验以下假设：与PRRS疫情高发猪场相比，PRRS疫情低发猪场的生物安全脆弱性评分存在差异。在使用的两个数据库中，评分始终表明得分较高的猪场PRRS疫情发生频率更高。在第一次验证中，与有2次或更多疫情的猪场（0.43；0.39 - 0.46）相比，之前从未进行过疫情调查的猪场得分显著更低（p < 0.02）（0.29；0.21 - 0.37）。在第二次验证中，与病例组（0.35；0.33 - 0.38）相比，对照组猪场得分也显著更低（p < 0.004）（0.30；0.27 - 0.33）。此外，结果表明与猪只移动、空气和水传播以及人员移动相关的事件应被优先考虑。生物安全脆弱性评分可能有助于评估生物安全协议中的脆弱性，以降低PRRS疫情的发生频率，并可能帮助生产者和兽医随着时间推移确定改善生物安全措施的投资优先级。
