Fielding Helen R, McKinley Trevelyan J, Delahay Richard J, Silk Matthew J, McDonald Robbie A
Environment and Sustainability Institute, Mathematics and Physical Sciences, University of Exeter, Penryn Campus, Penryn TR10 9FE, UK.
The Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK.
R Soc Open Sci. 2020 Apr 22;7(4):191806. doi: 10.1098/rsos.191806. eCollection 2020 Apr.
Trading animals between farms and via markets can provide a conduit for spread of infections. By studying trading networks, we might better understand the dynamics of livestock diseases. We constructed ingoing contact chains of cattle farms in Great Britain that were linked by trading, to elucidate potential pathways for the transmission of infection and to evaluate their effect on the risk of a farm experiencing a bovine tuberculosis (bTB) incident. Our findings are consistent with variation in bTB risk associated with region, herd size, disease risk area and history of previous bTB incidents on the root farm and nearby farms. However, we also identified effects of both direct and indirect trading patterns, such that connections to more farms in the England High-Risk Area up to three movements away from the root farm increased the odds of a bTB incident, while connections with more farms in the England Low-Risk Area up to eight movements away decreased the odds. Relative to other risk factors for bTB, trading behaviours are arguably more amenable to change, and consideration of risks associated with indirect trading, as well direct trading, might therefore offer an additional approach to bTB control in Great Britain.
农场之间以及通过市场进行动物交易可能成为感染传播的渠道。通过研究交易网络，我们或许能更好地理解家畜疾病的动态。我们构建了英国通过交易相连的养牛场的传入联系链，以阐明感染传播的潜在途径，并评估其对农场发生牛结核病（bTB）事件风险的影响。我们的研究结果与bTB风险因地区、畜群规模、疾病风险区域以及根源农场和附近农场之前的bTB事件历史而产生的差异一致。然而，我们还发现了直接和间接交易模式的影响，即与根源农场距离达三次交易行程以内的英格兰高风险地区更多农场建立联系会增加发生bTB事件的几率，而与距离达八次交易行程以内的英格兰低风险地区更多农场建立联系则会降低几率。相对于bTB的其他风险因素而言，交易行为更有可能加以改变，因此考虑直接交易以及间接交易相关的风险，可能会为英国的bTB防控提供一种额外的方法。
