Illinois Natural History Survey-Prairie Research Institute, University of Illinois Urbana-Champaign, Champaign, IL, USA.
Department of Pathobiology, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL, USA.
Transbound Emerg Dis. 2021 Jul;68(4):2376-2383. doi: 10.1111/tbed.13901. Epub 2020 Nov 17.
Understanding the geographic distribution and clustering of chronic wasting disease (CWD) among free-ranging white-tailed deer (Odocoileus virginianus) populations can inform disease management practices. We used a retrospective analysis of surveillance data to evaluate CWD's spatial and temporal dynamics within 16 CWD-infected northern Illinois counties. Of 42,541 deer samples collected and tested for CWD from recreational hunter harvest between 2008 and 2019, we recorded 359 (0.84%) CWD-positive samples. We observed variability in CWD cases over time and space. By county, the median CWD-positive proportion was 0.84%, varying from a minimum of 0.14% in McHenry County to a maximum of 6.28% in Boone County. Across years, there were differences among CWD-positive proportions with a median of 0.90%, ranging from a minimum of 0.27% in 2012 to a maximum of 1.60% in 2019. We used a retrospective discrete Poisson scan statistic model to evaluate the space-time clustering of CWD-positive deer. We identified a statistically significant (p < .001) primary cluster C1 (area = 23.59 km ; RR = 10.48), occurring from 2010 to 2015 in the north-central part of the study area, and a secondary cluster C2, occurring from 2014 to 2019 (area = 9.27 km ; RR = 3.88) in the north-west of the study area. Detected CWD-positive space-time clusters suggest that the risk of CWD is not random. Space-time clusters of CWD can be used to evaluate the effectiveness of the Illinois CWD management programme. The area surrounding the older C1 cluster has undergone longer and more intense CWD management compared with C2. Currently, the older C1 cluster is no longer as high risk compared with the newer cluster C2, suggesting that management efforts in C2 should be increased. However, all CWD clusters should be targeted with surveillance, prevention and management programmes, including reducing deer densities to limit further spread of CWD.
了解自由放养白尾鹿（Odocoileus virginianus）种群中慢性消耗病（CWD）的地理分布和聚集情况，可以为疾病管理实践提供信息。我们使用回顾性分析监测数据来评估伊利诺伊州北部 16 个感染 CWD 的县的 CWD 时空动态。在 2008 年至 2019 年期间，从娱乐性猎人捕获的 42541 只鹿的样本中，我们记录了 359 个（0.84%）CWD 阳性样本。我们观察到 CWD 病例在时间和空间上存在变化。按县划分，CWD 阳性比例的中位数为 0.84%，从麦克亨利县的最低 0.14%到布恩县的最高 6.28%不等。在不同年份中，CWD 阳性比例也存在差异，中位数为 0.90%，从 2012 年的最低 0.27%到 2019 年的最高 1.60%不等。我们使用回顾性离散泊松扫描统计模型来评估 CWD 阳性鹿的时空聚类。我们确定了一个具有统计学意义的（p<.001）主要聚类 C1（面积 23.59km2；RR 10.48），发生在研究区域的中北部，从 2010 年到 2015 年，以及一个次要聚类 C2，发生在研究区域的西北部，从 2014 年到 2019 年（面积 9.27km2；RR 3.88）。检测到的 CWD 阳性时空聚类表明，CWD 的风险并非随机的。CWD 的时空聚类可用于评估伊利诺伊州 CWD 管理计划的有效性。与 C2 相比，较旧的 C1 聚类周围的区域经历了更长时间和更密集的 CWD 管理。目前，与较新的 C2 聚类相比，较旧的 C1 聚类的风险较低，这表明应增加 C2 中的管理工作。然而，所有的 CWD 聚类都应该通过监测、预防和管理计划来靶向，包括降低鹿的密度以限制 CWD 的进一步传播。
