Islam Md Rafiul, Bulut Ummugul, Feria-Arroyo Teresa Patricia, Tyshenko Michael G, Oraby Tamer
Department of Mathematics, Iowa State University, Ames, IA, United States.
Department of Mathematical, Physical, and Engineering Sciences, Texas A&M University-San Antonio, San Antonio, TX, United States.
Front Epidemiol. 2022 May 26;2:889280. doi: 10.3389/fepid.2022.889280. eCollection 2022.
Chronic wasting disease (CWD) is a spongiform encephalopathy disease caused by the transmission of infectious prion agents. CWD is a fatal disease that affects wild and farmed cervids in North America with few cases reported overseas. Social interaction of cervids, feeding practices by wildlife keepers and climate effects on the environmental carrying capacity all can affect CWD transmission in deer. Wildlife deer game hunting is economically important to the semi-arid South Texas region and is affected by climate change. In this paper, we model and investigate the effect of climate change on the spread of CWD using typical climate scenarios. We use a system of impulsive differential equations to depict the transmission of CWD between different age groups and gender of cervids. The carrying capacity and contact rates are assumed to depend on climate. Due to the polygamy of bucks, we use mating rates that depend on the number of bucks and does. We analyze the stability of the model and use simulations to study the effect of harvesting (culling) on eradicating the disease, given the climate of South Texas. We use typical climate change scenarios based on published data and our assumptions. For the climate indicator, we calculated and utilized the Standard Precipitation Evapotranspiration Index (SPEI). We found that climate change might hinder the efforts to reduce and effectively manage CWD as it becomes endemic to South Texas. The model shows the extinction of the deer population from this region is a likely outcome.
慢性消耗病（CWD）是一种由传染性朊病毒传播引起的海绵状脑病。CWD是一种致命疾病，影响北美野生和养殖的鹿科动物，海外仅有少数病例报告。鹿科动物的社交互动、野生动物饲养员的喂养方式以及气候对环境承载能力的影响，都会影响鹿群中CWD的传播。野生鹿狩猎对半干旱的南德克萨斯地区具有重要经济意义，且受到气候变化的影响。在本文中，我们使用典型气候情景对气候变化对CWD传播的影响进行建模和研究。我们使用脉冲微分方程组来描述CWD在鹿科动物不同年龄组和性别之间的传播。假设承载能力和接触率取决于气候。由于雄鹿的一夫多妻制，我们使用取决于雄鹿和雌鹿数量的交配率。我们分析了模型的稳定性，并利用模拟研究了在南德克萨斯气候条件下，捕杀（淘汰）对根除该疾病的影响。我们根据已发表的数据和假设使用典型的气候变化情景。对于气候指标，我们计算并利用了标准降水蒸散指数（SPEI）。我们发现，随着CWD在南德克萨斯成为地方病，气候变化可能会阻碍减少和有效管理该疾病的努力。该模型表明，该地区鹿群灭绝可能是一个结果。
