Hearst Scoty, Huang Miranda, Johnson Bryant, Rummells Elijah
The Department of Chemistry and Biochemistry, Mississippi College, Clinton, MS 39056, USA.
Department of Wildlife, Fisheries, and Aquaculture, Mississippi State University, Starkville, MS 39762, USA.
Animals (Basel). 2023 Mar 26;13(7):1171. doi: 10.3390/ani13071171.
White-tailed deer (, WTD) spread communicable diseases such the zoonotic coronavirus SARS-CoV-2, which is a major public health concern, and chronic wasting disease (CWD), a fatal, highly contagious prion disease occurring in cervids. Currently, it is not well understood how WTD are spreading these diseases. In this paper, we speculate that "super-spreaders" mediate disease transmission via direct social interactions and indirectly via body fluids exchanged at scrape sites. Super-spreaders are infected individuals that infect more contacts than other infectious individuals within a population. In this study, we used network analysis from scrape visitation data to identify potential super-spreaders among multiple communities of a rural WTD herd. We combined local network communities to form a large region-wide social network consisting of 96 male WTD. Analysis of WTD bachelor groups and random network modeling demonstrated that scraping networks depict real social networks, allowing detection of direct and indirect contacts, which could spread diseases. Using this regional network, we model three major types of potential super-spreaders of communicable disease: in-degree, out-degree, and betweenness potential super-spreaders. We found out-degree and betweenness potential super-spreaders to be critical for disease transmission across multiple communities. Analysis of age structure revealed that potential super-spreaders were mostly young males, less than 2.5 years of age. We also used social network analysis to measure the outbreak potential across the landscape using a new technique to locate disease transmission hotspots. To model indirect transmission risk, we developed the first scrape-to-scrape network model demonstrating connectivity of scrape sites. Comparing scrape betweenness scores allowed us to locate high-risk transmission crossroads between communities. We also monitored predator activity, hunting activity, and hunter harvests to better understand how predation influences social networks and potential disease transmission. We found that predator activity significantly influenced the age structure of scraping communities. We assessed disease-management strategies by social-network modeling using hunter harvests or removal of potential super-spreaders, which fragmented WTD social networks reducing the potential spread of disease. Overall, this study demonstrates a model capable of predicting potential super-spreaders of diseases, outlines methods to locate transmission hotspots and community crossroads, and provides new insight for disease management and outbreak prevention strategies.
白尾鹿（WTD）传播诸如人畜共患冠状病毒SARS-CoV-2等传染病，这是一个重大的公共卫生问题，同时还传播慢性消耗病（CWD），一种发生在鹿科动物中的致命性、高传染性朊病毒疾病。目前，人们对WTD如何传播这些疾病还了解甚少。在本文中，我们推测“超级传播者”通过直接的社交互动以及间接通过在擦痕处交换的体液来介导疾病传播。超级传播者是指在一个种群中比其他感染个体感染更多接触者的受感染个体。在本研究中，我们利用擦痕访问数据进行网络分析，以识别一个农村WTD鹿群多个群落中的潜在超级传播者。我们将局部网络群落合并，形成了一个由96只雄性WTD组成的大型区域范围社交网络。对WTD单身群体的分析和随机网络建模表明，擦痕网络描绘了真实的社交网络，能够检测到可能传播疾病的直接和间接接触。利用这个区域网络，我们对传染病的三种主要潜在超级传播者类型进行了建模：入度、出度和中介中心性潜在超级传播者。我们发现出度和中介中心性潜在超级传播者对于跨多个群落的疾病传播至关重要。年龄结构分析表明，潜在超级传播者大多是年龄小于2.5岁的年轻雄性。我们还利用社交网络分析，采用一种定位疾病传播热点的新技术，来衡量整个区域的疫情爆发潜力。为了模拟间接传播风险，我们开发了第一个擦痕到擦痕的网络模型，展示了擦痕地点的连通性。比较擦痕中介中心性得分使我们能够定位群落之间的高风险传播交叉点。我们还监测了捕食者活动、狩猎活动和猎人收获情况，以更好地了解捕食如何影响社交网络和潜在疾病传播。我们发现捕食者活动显著影响了擦痕群落的年龄结构。我们通过社交网络建模评估了疾病管理策略，即利用猎人收获或清除潜在超级传播者，这会使WTD社交网络碎片化，从而降低疾病的潜在传播。总体而言，本研究展示了一个能够预测疾病潜在超级传播者的模型，概述了定位传播热点和群落交叉点的方法，并为疾病管理和疫情预防策略提供了新的见解。
