Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
Wellington-Dufferin Guelph Public Health, Guelph, Ontario, Canada.
Zoonoses Public Health. 2022 Aug;69(5):425-438. doi: 10.1111/zph.12931. Epub 2022 Mar 13.
Cryptosporidium is a protozoan parasite of increasing global public health concern because of its ability to cause disease in both humans and animals through contaminated food and water supplies. In Canada, most human cryptosporidiosis cases are due to Cryptosporidium hominis; however, the presence of zoonotic Cryptosporidium parvum has been observed. Since 2005, the incidence of cryptosporidiosis in Ontario has been consistently higher than the national average; however, it is not understood why, suggesting an incomplete understanding of the pathogen's ecology, epidemiology and transmission pathways. The goal of this study was to explore the spatial distribution of human cryptosporidiosis across the 29 Public Health Unit (PHU) areas of Southern Ontario from 2011 to 2014. Surveillance data on human cryptosporidiosis were obtained from Public Health Ontario. Choropleth and isopleth maps were used to display the distribution of incidence rates of human cryptosporidiosis. High-rate clusters of human cryptosporidiosis were identified. Poisson and spatial Poisson regression models were used to determine the relationship between the incidence of human cryptosporidiosis, cattle density and the smoothed farm-level prevalence of bovine cryptosporidiosis at the PHU level. The annual incidence of reported human cryptosporidiosis in Southern Ontario ranged from 1.62 (95% CI: 1.41-1.86) to 1.82 (95%CI: 1.60-2.06) cases per 100,000 population, with an overall cumulative incidence of 6.91 (95%CI: 6.47-7.39) cases per 100,000 for the 4-year study period. High-risk clusters of human cryptosporidiosis were identified in each year. The relative risk for the clusters ranged from 2.03 (95% CI: 1.63-2.55) to 6.87 (95% CI: 5.07-9.30). A relationship was found between the incidence of cryptosporidiosis and dairy cattle density. Based on this study, the Central West region would be an ideal ecological system to conduct further targeted surveillance to identify factors that may be contributing to the higher burden of cryptosporidiosis in the human and bovine populations in the region.
隐孢子虫是一种原生动物寄生虫，由于其能够通过受污染的食物和水供应在人类和动物中引起疾病，因此对全球公共卫生的关注日益增加。在加拿大，大多数人类隐孢子虫病是由人隐孢子虫引起的;然而，已经观察到了动物源隐孢子虫的存在。自 2005 年以来，安大略省的隐孢子虫病发病率一直高于全国平均水平;然而，原因尚不清楚，这表明人们对病原体的生态学、流行病学和传播途径了解不完整。本研究的目的是探索 2011 年至 2014 年期间安大略省南部 29 个公共卫生单位(PHU)地区人类隐孢子虫病的空间分布。从安大略省公共卫生局获得了关于人类隐孢子虫病的监测数据。使用等值线和等间距图显示人类隐孢子虫病发病率的分布。确定了人类隐孢子虫病高发率的集群。使用泊松和空间泊松回归模型来确定 PHU 级人类隐孢子虫病的发病率、牛密度以及牛隐孢子虫病的平滑农场级流行率之间的关系。安大略省南部报告的人类隐孢子虫病的年发病率范围为每 10 万人 1.62(95%CI:1.41-1.86)至 1.82(95%CI:1.60-2.06)例，4 年研究期间的累计发病率为每 10 万人 6.91(95%CI:6.47-7.39)例。每年都确定了人类隐孢子虫病的高风险集群。集群的相对风险范围为 2.03(95%CI:1.63-2.55)至 6.87(95%CI:5.07-9.30)。发现隐孢子虫病的发病率与奶牛密度之间存在关系。基于本研究，中西部地区将是一个理想的生态系统，可进行进一步的有针对性监测，以确定可能导致该地区人类和牛群隐孢子虫病负担更高的因素。
