Assessing risks of toxoplasmosis in wildlife in the Canadian North

评估加拿大北部野生动物感染弓形虫病的风险

• 批准号: RGPIN-2018-04900
• 负责人: Jenkins, Emily
• 金额: $ 6.85万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=766041
• 关键词: Assessing; risks; toxoplasmosis; wildlife; Canadian

Toxoplasma gondii is arguably the most successful parasite in the world, infecting most warm blooded animals. Cats (domestic and wild) serve as the only definitive hosts. Despite the general absence of cats in the Canadian Arctic, Inuit in Nunavut and Nunavik (northern Québec) show levels of exposure to Toxoplasma 2-4 times higher than that of the general North American population. Arctic wildlife also show evidence of exposure to Toxoplasma, especially terrestrial carnivores and marine mammals. There are multiple hypotheses and controversies about how Toxoplasma is introduced and maintained in the Arctic. Therefore, the overarching goal of this research program is to determine sources of infection, transmission routes, and impact of toxoplasmosis on Arctic wildlife important for conservation and human harvest across the Canadian Arctic. A secondary goal is to encourage safe country food consumption through validation and creation of local capacity to test harvested wildlife. We will use state-of-the techniques to determine if Canadian lynx are a local source of Toxoplasma in the North (Obj. 1). We will test wildlife (such as geese, caribou, and marine mammals) harvested by hunters and foods prepared from wildlife to determine which wildlife species and tissues are infected (Obj. 2), and if traditional methods of food preparation inactivate the parasite (Obj. 3). We will build local capacity to perform food safety testing under low resource conditions in the Canadian Arctic, using a validated test which requires little or no specialized equipment. Through long-term field studies and pathological examination of Arctic wildlife, we will determine if the parasite affects survival and reproduction of affected animals (Obj. 4). In addition, we will compare strains of Arctic Toxoplasma to those of the parasite from temperate regions to determine the source of exposure for Arctic wildlife and people (Obj. 5). This research program directly addresses community concerns about the safety of country foods which are of cultural, nutritional, and economic significance in the Canadian North, where levels of food insecurity are significantly higher than the national average. This work also has implications for wildlife management and conservation, since this parasite can reduce reproductive success and alter behavior to increase predation risk. As well, this work has relevance to human health, as the parasite can be dangerous in people with decreased immunity or in fetuses of mothers infected for the first time in pregnancy. Finally, this program provides the basis for understanding and predicting the effects of a rapidly changing climate on the distribution and transmission of a pathogenic parasite. This work will provide critically needed evidence for assessing, predicting, and mitigating risks of Toxoplasma for wildlife and people in the rapidly changing Canadian North.

刚地弓形虫可以说是世界上最成功的寄生虫，可以感染大多数温血动物。猫（家猫和野猫）是唯一的最终宿主。尽管加拿大北极地区普遍没有猫，但努纳武特和努纳维克（quacimbec北部）的因纽特人暴露于弓形虫的水平比一般北美人口高2-4倍。北极野生动物也有接触弓形虫的证据，特别是陆生食肉动物和海洋哺乳动物。关于弓形虫是如何在北极引入和维持的，存在多种假设和争议。因此，本研究项目的首要目标是确定感染源、传播途径以及弓形虫病对北极野生动物的影响，这对加拿大北极地区的保护和人类收获至关重要。第二个目标是通过验证和建立当地检验收获野生动物的能力，鼓励安全的国家食品消费。我们将使用最新的技术来确定加拿大猞猁是否是北方弓形虫的当地来源（Obj. 1）。我们将测试猎人捕获的野生动物（如鹅、驯鹿和海洋哺乳动物）和从野生动物制备的食物，以确定哪些野生动物物种和组织被感染（任务2），以及传统的食物制备方法是否灭活了寄生虫（任务3）。我们将建立在加拿大北极地区资源匮乏条件下进行食品安全检测的当地能力，使用一种经过验证的测试，这种测试只需要很少或不需要专门设备。通过对北极野生动物的长期实地研究和病理检查，我们将确定寄生虫是否影响受感染动物的生存和繁殖（Obj. 4）。此外，我们将比较北极弓形虫与温带地区弓形虫的菌株，以确定北极野生动物和人类的暴露源（Obj. 5）。该研究项目直接解决了社区对乡村食品安全的担忧，这些食品在加拿大北部具有文化、营养和经济意义，那里的食品不安全水平明显高于全国平均水平。这项研究对野生动物的管理和保护也有意义，因为这种寄生虫会降低繁殖成功率，改变行为，增加被捕食的风险。此外，这项工作与人类健康有关，因为这种寄生虫对免疫力下降的人或首次怀孕感染的母亲的胎儿可能是危险的。最后，该项目为理解和预测快速变化的气候对致病性寄生虫分布和传播的影响提供了基础。这项工作将为评估、预测和减轻弓形虫对快速变化的加拿大北部野生动物和人类的风险提供急需的证据。