Department of Pathobiology, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Guelph ON N1G 2W1, Canada; Canadian Wildlife Health Cooperative, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Guelph ON N1G 2W1, Canada.
Department of Population Medicine, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Guelph ON N1G 2W1, Canada.
Spat Spatiotemporal Epidemiol. 2020 Nov;35:100371. doi: 10.1016/j.sste.2020.100371. Epub 2020 Aug 5.
Baylisascaris procyonis, the raccoon roundworm, is a parasite found throughout North America and parts of Europe. More than 150 species of mammals and birds including humans can develop neurological disease following infection with the larval stage of this parasite. To investigate whether B. procyonis infections in raccoons cluster in space, time, or space-time, we used data from 1353 Ontario raccoons submitted to the Canadian Wildlife Health Cooperative between 2013 and 2016. We identified a significant spatial cluster of increased infection prevalence in southern Ontario centered over a major metropolitan area, as well as a significant cluster of decreased infection prevalence in a primarily agricultural region in southwestern Ontario. Furthermore, we identified statistically significant temporal clusters in the fall in annual scans of data from 2014, 2015 and 2016. Examination of both Bernoulli and space-time permutation models for space-time analysis suggested that the purely spatial and temporal clusters were not explained by relatively short and spatially discrete events in space-time. The identified annual temporal clusters are consistent with previous research on the seasonality of B. procyonis infection in raccoons. Recognition of the spatial infection clusters will help identify potential geographic and anthropogenic factors associated with the occurrence of B. procyonis infection in raccoons. Given the zoonotic potential of this parasite, identification of a cluster of high infection prevalence in a major metropolitan area has implications for public education and risk management strategies.
浣熊蛔虫，又称浣熊圆线虫，是一种分布于北美洲和部分欧洲地区的寄生虫。超过 150 种哺乳动物和鸟类，包括人类，在感染这种寄生虫的幼虫阶段后可能会发展出神经系统疾病。为了研究浣熊的贝氏蛔虫感染是否在空间、时间或时空上聚集，我们使用了 2013 年至 2016 年间，1353 只安大略省浣熊向加拿大野生动物健康合作组织提交的数据。我们发现，在安大略省南部，一个主要大都市地区为中心的区域，感染率显著增加，而在安大略省西南部一个主要农业区，感染率显著降低，存在明显的空间聚类。此外，我们还在 2014 年、2015 年和 2016 年的年度扫描数据中发现了具有统计学意义的秋季时间聚类。对时空分析中的 Bernoulli 和时空置换模型的检验表明，纯粹的时空聚类不能用时空上相对较短且离散的事件来解释。所识别的年度时间聚类与以前关于浣熊贝氏蛔虫感染季节性的研究一致。认识到空间感染聚类将有助于确定与浣熊贝氏蛔虫感染发生相关的潜在地理和人为因素。鉴于这种寄生虫的人畜共患潜力，在一个主要大都市地区发现高感染率的聚类，对公众教育和风险管理策略具有重要意义。
