Toxoplasma gondii and related Sarcocystidae parasites in harvested caribou from Nunavik, Canada.

Caribou are keystone species important for human harvest and of conservation concern; even so, much is unknown about the impact of parasites on caribou health and ecology. The aim of this study was to determine the seroprevalence, tissue prevalence, and diversity of tissue-dwelling coccidian parasites (including , and spp.) in 88 migratory caribou () harvested for human consumption in two communities in Nunavik, Québec, Canada. Both have potential to cause abortions and neurological disease in caribou. Seroprevalence for antibodies to using ELISA on fluid from thawed hearts was 18% overall, and no DNA of was detected in tissues, which has positive implications for food safety since this parasite is zoonotic. Seroprevalence for antibodies to using competitive ELISA was 5%, and DNA of was detected in only one heart sample. DNA of , a non-zoonotic, related coccidian, was detected in tissue samples from 85% of caribou, with higher prevalence in heart (82%) than skeletal muscle (47%). This is the first time that spp. from caribou in Canada have been identified to species level, many of which have been described in reindeer from Fennoscandia. The high prevalence and diversity of spp. suggests intact trophic relationships between canids and caribou in Nunavik. spp. was serendipitously detected in three muscle samples, a parasite previously associated with skin lesions in caribou in Nunavik. Community-level differences in exposure and prevalence of spp. in skeletal muscle tissues may reflect differences in hunter selection of individual animals and muscles, or possibly regional differences in the ecology of carnivore definitive hosts for these parasites. Further work is needed to explore effects of tissue coccidians in caribou, their taxonomic classifications, and community level differences in parasite prevalence and diversity.