Lichoti Jacqueline Kasiiti, Davies Jocelyn, Kitala Philip M, Githigia Samuel M, Okoth Edward, Maru Yiheyis, Bukachi Salome A, Bishop Richard P
Ministry of Agriculture, Livestock and Fisheries, State Department of Veterinary Services, Private Bag-00625, Nairobi, Kenya; University of Nairobi, Department of Public Health, Pharmacology and Toxicology, P.O. Box 29053, Nairobi 00625, Kenya.
Commonwealth Scientific and Industrial Research Organization, Land and Water Flagship, Business & Innovation Centre, Desert Knowledge Precinct, Alice Springs 0870, NT, Australia.
Prev Vet Med. 2016 Apr 1;126:1-10. doi: 10.1016/j.prevetmed.2016.01.019. Epub 2016 Jan 25.
Pig movements play a significant role in the spread of economically important infectious diseases such as the African swine fever. Characterization of movement networks between pig farms and through other types of farm and household enterprises that are involved in pig value chains can provide useful information on the role that different participants in the networks play in pathogen transmission. Analysis of social networks that underpin these pig movements can reveal pathways that are important in the transmission of disease, trade in commodities, the dissemination of information and the influence of behavioural norms. We assessed pig movements among pig keeping households within West Kenya and East Uganda and across the shared Kenya-Uganda border in the study region, to gain insight into within-country and trans-boundary pig movements. Villages were sampled using a randomized cluster design. Data were collected through interviews in 2012 and 2013 from 683 smallholder pig-keeping households in 34 villages. NodeXL software was used to describe pig movement networks at village level. The pig movement and trade networks were localized and based on close social networks involving family ties, friendships and relationships with neighbours. Pig movement network modularity ranged from 0.2 to 0.5 and exhibited good community structure within the network implying an easy flow of knowledge and adoption of new attitudes and beliefs, but also promoting an enhanced rate of disease transmission. The average path length of 5 defined using NodeXL, indicated that disease could easily reach every node in a cluster. Cross-border boar service between Uganda and Kenya was also recorded. Unmonitored trade in both directions was prevalent. While most pig transactions in the absence of disease, were at a small scale (<5km) and characterized by regular agistment, most pig sales during ASF outbreaks were to traders or other farmers from outside the sellers' village at a range of >10km. The close social relationships between actors in pig movement networks indicate the potential for possible interventions to develop shared norms and mutually accepted protocols amongst smallholder pig keepers to better manage the risk of ASF introduction and transmission.
猪的流动在诸如非洲猪瘟等具有经济重要性的传染病传播中起着重要作用。对猪场之间以及通过参与生猪价值链的其他类型农场和家庭企业的流动网络进行特征描述，可以提供有关网络中不同参与者在病原体传播中所起作用的有用信息。对支撑这些猪流动的社会网络进行分析，可以揭示在疾病传播、商品贸易、信息传播以及行为规范影响方面重要的途径。我们评估了肯尼亚西部和乌干达东部养猪户之间以及研究区域内肯尼亚 - 乌干达共同边界的猪流动情况，以深入了解国内和跨境猪流动情况。采用随机整群设计对村庄进行抽样。2012年和2013年通过对34个村庄的683个小农户养猪户进行访谈收集数据。使用NodeXL软件描述村庄层面的猪流动网络。猪的流动和贸易网络是本地化的，基于涉及家庭关系、友谊和与邻居关系的紧密社会网络。猪流动网络的模块性范围为0.2至0.5，在网络内呈现出良好的社区结构，这意味着知识易于传播以及新态度和信念易于采纳，但同时也促进了疾病传播速度的提高。使用NodeXL定义的平均路径长度为5，表明疾病可以很容易地到达集群中的每个节点。还记录了乌干达和肯尼亚之间的跨境公猪服务。双向的无监管贸易很普遍。在没有疾病的情况下，大多数猪交易规模较小（<5公里），其特点是定期寄养，而在非洲猪瘟疫情爆发期间，大多数猪销售是卖给距离卖方村庄超过10公里的外地商人或其他农民。猪流动网络中参与者之间密切的社会关系表明，有可能进行干预，以在小农户养猪户中制定共同规范和相互接受的协议，从而更好地管理非洲猪瘟传入和传播的风险。
