Sansamur Chalutwan, Wiratsudakul Anuwat, Charoenpanyanet Arisara, Punyapornwithaya Veerasak
Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand.
Department of Clinical Sciences and Public Health and The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Phutthamonthon, Nakhon Pathom 73170, Thailand.
Vet Sci. 2020 Sep 19;7(3):138. doi: 10.3390/vetsci7030138.
Animal movement is one of the most important risk factors for outbreaks of foot and mouth disease (FMD) in cattle. Likewise, FMD can spread to cattle farms via vehicles contaminated with the FMD virus. In Northern Thailand, the movement of manure transport vehicles and the circulation of manure bags among cattle farms are considered as potential risk factors for FMD outbreaks among cattle farms. This study aimed to determine the characteristics and movement patterns of manure tradesman using social network analysis. A structured questionnaire was used to identify sequences of farms routinely visited by each tradesman. A total of 611 participants were interviewed, including 154 beef farmers, 407 dairy farmers, 36 tradesmen, and 14 final purchasers. A static weighted directed one-mode network was constructed, and the network metrics were measured. For the manure tradesman-cattle farmer network, the tradesman possessed the highest value of in- and out-degree centralities (71 and 4), betweenness centralities (114.5), and k-core values (2). These results indicated that the tradesman had a high frequency of farm visits and had a remarkable influence on other persons (nodes) in the network. The movement of vehicles ranged from within local districts, among districts, or even across provinces. Unclean manure plastic bags were circulated among cattle farms. Therefore, both vehicles and the bags may act as a disease fomite. Interestingly, no recording system was implemented for the movement of manure transport vehicles. This study suggested that the relevant authority and stakeholders should be aware of the risk of FMD spreading within this manure trading network. The findings from this study can be used as supporting data that can be used for enhancing FMD control measures, especially for FMD endemic areas.
动物移动是牛群口蹄疫（FMD）暴发的最重要风险因素之一。同样，口蹄疫可通过被口蹄疫病毒污染的车辆传播至养牛场。在泰国北部，粪便运输车辆的移动以及牛粪袋在各养牛场之间的流通被视为养牛场口蹄疫暴发的潜在风险因素。本研究旨在通过社会网络分析确定粪便商人的特征和移动模式。采用结构化问卷来识别每位商人常规走访的农场序列。共采访了611名参与者，包括154名肉牛养殖户、407名奶牛养殖户、36名商人以及14名最终购买者。构建了一个静态加权有向单模网络，并对网络指标进行了测量。对于粪便商人 - 养牛户网络，商人的入度中心性和出度中心性值最高（分别为71和4），中介中心性值为114.5，k - 核值为2。这些结果表明，商人走访农场的频率很高，并且对网络中的其他人（节点）有显著影响。车辆的移动范围包括在当地不同区域内、不同区域之间，甚至跨省。不干净的牛粪塑料袋在各养牛场之间流通。因此，车辆和袋子都可能成为疾病传播媒介。有趣的是，对于粪便运输车辆的移动没有实施记录系统。本研究表明，相关当局和利益相关者应意识到口蹄疫在这个粪便交易网络内传播的风险。本研究结果可作为支持性数据，用于加强口蹄疫防控措施，特别是对口蹄疫流行地区。
