Assessing risks of toxoplasmosis in wildlife in the Canadian North

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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.