Use of stable isotopes to reveal trophic relationships and transmission of a food-borne pathogen.

Predators in food webs are valuable sentinel species for zoonotic and multi-host pathogens such as Toxoplasma gondii. This protozoan parasite is ubiquitous in warm-blooded vertebrates, and can have serious adverse effects in immunocompromised hosts and foetuses. In northern ecosystems, T. gondii is disproportionately prevalent in Inuit people and wildlife, in part due to multiple routes of transmission. We combined data on T. gondii infection in foxes from Nunavik (northern Québec, Canada) with stable isotope data tracking trophic relationships between foxes and several of their main prey species. Red (Vulpes vulpes) and Arctic fox (Vulpes lagopus) carcasses were collected by local trappers from 2015 to 2019. We used magnetic capture PCR to detect DNA of T. gondii in heart and brain tissues, and enzyme-linked immunosorbent assay to detect antibodies in blood. By linking infection status with diet composition, we showed that infected foxes had a higher probability of consuming aquatic prey and migratory geese, suggesting that these may be important sources of T. gondii transmission in the Arctic. This use of stable isotopes to reveal parasite transmission pathways can be applied more broadly to other foodborne pathogens, and provides evidence to assess and mitigate potential human and animal health risks associated with T. gondii in northern ecosystems.

Barriers and opportunities for improving dog bite prevention and dog management practices in northern Indigenous communities.

Globally, people living in northern Indigenous communities are at higher risk of dog bites than the rest of the population living in North America, with annual incidence ranging from 0.61 to 59.6/10,000 inhabitants. Considering that rabies is endemic in wild canid populations in certain regions of the Arctic, the prevention of dog bites and the management of dog populations are of crucial importance for public health in these contexts. Most northern communities lack access to veterinary services, mainly due to their remote geographical location and to limited financial resources. Currently, northern Indigenous communities are using different approaches and strategies to prevent dog bites and manage dog populations, but the effectiveness of these approaches sometimes lacks evidence, and their low acceptability may affect their implementation. This study aims to describe (1) the current access and uses of veterinary services, and (2) the perceived barriers and opportunities related to dog population management practices currently implemented, or that could be implemented, in a Naskapi community and an Innu community located in northern Quebec (Canada). Quantitative data were collected through a survey to inhabitants on veterinary services (n = 122). Qualitative data were collected using individual interviews to inhabitants and health professionals to describe how dog population management measures were perceived, and to identify barriers and opportunities related to their implementation (n = 37). Descriptive and inferential analysis (quantitative data) and thematic analysis (qualitative data) were performed. Results show that the two main measures implemented at the time of the study - dog culling and short-duration veterinary clinics - were not perceived as fully acceptable and sustainable. Reinforcing access to veterinary services and other dog-related services, such as shelters and training programs on dogs, was identified as a need to improve dog bites prevention and dog population management in remote Indigenous communities. The implementation of animal health measures should be decided by concerned Indigenous communities to follow decolonial practices. It includes ensuring informed consent of dog owners, improving communication before, during and after interventions, separating veterinary services from rehoming and, most importantly giving back to Indigenous communities the complete leadership over animal health in their communities.

Low levels of genetic differentiation and structure in red fox populations in Eastern Canada and implications for Arctic fox rabies propagation potential.

Rabies is a lethal zoonosis present in most parts of the world which can be transmitted to humans through the bite from an infected mammalian reservoir host. The Arctic rabies virus variant (ARVV) persists mainly in populations of Arctic foxes (Vulpes lagopus), and to a lesser extent in red fox populations (Vulpes vulpes). Red foxes are thought to be responsible for sporadic southward movement waves of the ARVV outside the enzootic area of northern Canada. In this study, we wanted to investigate whether red foxes displayed notable levels of genetic structure across the Quebec-Labrador Peninsula, which includes portions of the provinces of Quebec and Newfoundland-Labrador in Canada, and is a region with a history of southward ARVV movement waves. We combined two datasets that were collected and genotyped using different protocols, totalling 675 red fox individuals across the whole region and genotyped across 13 microsatellite markers. We found two genetic clusters across the region, reflecting a latitudinal gradient, and characterized by low genetic differentiation. We also observed weak but significant isolation by distance, which seems to be marginally more important for females than for males. These findings suggest a general lack of resistance to movement in red fox populations across the Quebec-Labrador Peninsula, regardless of sex. Implications of these findings include additional support for the hypothesis of long-distance southward ARVV propagation through its red fox reservoir host.

Knowledge, attitudes, and practices regarding dogs and dog bites in Indigenous northern communities: A mixed methods study.

Introduction: The singular relationship developed over the years between northern Indigenous peoples and dogs has been profoundly changed through historical trauma, settlements and increased use of snowmobiles. Issues related to dogs have become increasingly complex and worrisome with the endemic presence of the rabies virus among Arctic fox populations, and given the fact that northern Indigenous peoples may have a higher risk of dog bites than the general population. This study aimed to investigate factors related to the risk of dog bites in Naskapi and Innu communities located in northern Quebec (Canada) by (1) describing the knowledge, attitudes and practices (KAP) regarding dogs and dog bites in these communities, and (2) analyzing experiences of inhabitants and health professionals with regard to dog bites and their management. Methods: A mixed methods study design that combined an observational cross-sectional survey and individual interviews was used. The survey collected data on KAP regarding dogs and dog bites among 122 respondents. Individual interviews (n = 37) were then conducted with victims of dog bites, owners of dogs that have bitten a person before, and health professionals. Descriptive and inferential analysis (quantitative data) and thematic analysis (qualitative data) were performed. Results and discussion: Results highlighted that 21% of respondents have had a dog bite in their lifetime. Most respondents were not aware of the risk of contracting rabies following a dog bite, although rabies risk perception was associated with risk perception of dogs (linear regression: coefficient = 0.69, 95% CI = 0.36-1.02). The odds of being more knowledgeable on rabies were higher (logistic regression: OR = 2.92, 95% CI = 1.07-7.98) among young adults. Dogs were perceived as both threats and protectors by community members. When the fear of dogs was present, it affected the quality of life of some inhabitants. There was confusion about responsibilities in the management of biting dogs, although protocols to follow after a bite were clear for health care professionals. This study revealed a lack of awareness and knowledge about dog bites and rabies risks in both communities. Results provide important knowledge for the development of interventions adapted to northern Indigenous communities.

Are foxes (Vulpes spp.) good sentinel species for Toxoplasma gondii in northern Canada?

BACKGROUND: In changing northern ecosystems, understanding the mechanisms of transmission of zoonotic pathogens, including the coccidian parasite Toxoplasma gondii, is essential to protect the health of vulnerable animals and humans. As high-level predators and scavengers, foxes represent a potentially sensitive indicator of the circulation of T. gondii in environments where humans co-exist. The objectives of our research were to compare serological and molecular assays to detect T. gondii, generate baseline data on T. gondii antibody and tissue prevalence in foxes in northern Canada, and compare regional seroprevalence in foxes with that in people from recently published surveys across northern Canada. METHODS: Fox carcasses (Vulpes vulpes/Vulpes lagopus, n = 749) were collected by local trappers from the eastern (Labrador and Québec) and western Canadian Arctic (northern Manitoba, Nunavut, and the Northwest Territories) during the winters of 2015-2019. Antibodies in heart fluid were detected using a commercial enzyme-linked immunosorbent assay. Toxoplasma gondii DNA was detected in hearts and brains using a magnetic capture DNA extraction and real-time PCR assay. RESULTS: Antibodies against T. gondii and DNA were detected in 36% and 27% of foxes, respectively. Detection of antibodies was higher in older (64%) compared to younger foxes (22%). More males (36%) than females (31%) were positive for antibodies to T. gondii. Tissue prevalence in foxes from western Nunavik (51%) was higher than in eastern Nunavik (19%). At the Canadian scale, T. gondii exposure was lower in western Inuit regions (13%) compared to eastern Inuit regions (39%), possibly because of regional differences in fox diet and/or environment. Exposure to T. gondii decreased at higher latitude and in foxes having moderate to little fat. Higher mean infection intensity was observed in Arctic foxes compared to red foxes. Fox and human seroprevalence showed similar trends across Inuit regions of Canada, but were less correlated in the eastern sub-Arctic, which may reflect regional differences in human dietary preferences. CONCLUSIONS: Our study sheds new light on the current status of T. gondii in foxes in northern Canada and shows that foxes serve as a good sentinel species for environmental circulation and, in some regions, human exposure to this parasite in the Arctic.

Ecology of Arctic rabies: 60 years of disease surveillance in the warming climate of northern Canada.

Rabies occurs throughout the Arctic, representing an ongoing public health concern for residents of northern communities. The Arctic fox (Vulpes lagopus) is the main reservoir of the Arctic rabies virus variant, yet little is known about the epidemiology of Arctic rabies, such as the ecological mechanisms driving where and when epizootics in fox populations occur. In this study, we provide the first portrait of the spatio-temporal spread of rabies across northern Canada. We also explore the impact of seasonal and multiannual dynamics in Arctic fox populations and climatic factors on rabies transmission dynamics. We analysed data on rabies cases collected through passive surveillance systems in the Yukon, Northwest Territories, Nunavut, Nunavik and Labrador from 1953 to 2014. In addition, we analysed a large and unique database of trapped foxes tested for rabies in the Northwest Territories and Nunavut from 1974 to 1984 as part of active surveillance studies. Rabies cases occurred in all Arctic regions of Canada and were relatively synchronous among foxes and dogs (Canis familiaris). This study highlights the spread of Arctic rabies virus variant across northern Canada, with contrasting rabies dynamics between different yet connected areas. Population fluctuations of Arctic fox populations could drive rabies transmission dynamics in a complex way across northern Canada. Furthermore, this study suggests different impacts of climate and sea ice cover on the onset of rabies epizootics in northern Canada. These results lay the groundwork for the development of epidemiological models to better predict the spatio-temporal dynamics of rabies occurrence in both wild and domestic carnivores, leading to better estimates of human exposure and transmission risk.

Occupations at risk of contracting zoonoses of public health significance in Québec.

INTRODUCTION: Climate change plays an important role in the geographic spread of zoonotic diseases. Knowing which populations are at risk of contracting these diseases is critical to informing public health policies and practices. In Québec, 14 zoonoses have been identified as important for public health to guide the climate change adaptation efforts of decision-makers and researchers. A great deal has been learned about these diseases in recent years, but information on at-risk workplaces remains incomplete. The objective of this study is to paint a portrait of the occupations and sectors of economic activity at risk for the acquisition of these zoonoses. METHODS: A rapid review of the scientific literature was conducted. Databases on the Ovid and EBSCO research platforms were searched for articles published between 1995 and 2018, in English and French, on 14 zoonoses (campylobacteriosis, cryptosporidiosis, verocytotoxigenic Escherichia coli, giardiasis, listeriosis, salmonellosis, Eastern equine encephalitis, Lyme disease, West Nile virus, food botulism, Q fever, avian and swine influenza, rabies, hantavirus pulmonary syndrome) and occupational health. The literature search retrieved 12,558 articles and, after elimination of duplicates, 6,838 articles were evaluated based on the title and the abstract. Eligible articles had to address both concepts of the research issue (prioritized zoonoses and worker health). Of the 621 articles deemed eligible, 110 were selected following their full reading. RESULTS: Of the diseases under study, enteric zoonoses were the most frequently reported. Agriculture, including veterinary services, public administration services and medical and social services were the sectors most frequently identified in the literature. CONCLUSION: The results of our study will support public health authorities and decision-makers in targeting those sectors and occupations that are particularly at risk for the acquisition of zoonoses. Doing so will ultimately optimize the public health practices of those responsible for the health of workers.

Exposure to Toxoplasma gondii Through Consumption of Raw or Undercooked Meat: A Systematic Review and Meta-Analysis.

Toxoplasma gondii is a globally distributed protozoan that mainly causes health issues in the fetuses of pregnant women who have never been exposed to this parasite and patients with deficient immune systems. Except in these vulnerable populations, the primary infection generally goes unnoticed in most healthy individuals. Apart from transplant/transfusion, congenital transmission, direct contact with infected cats or their feces, and environmental contamination (i.e., oocysts in food, water, and soil) pathways, humans can acquire the parasite through consumption of animal tissues infected by T. gondii. This meta-analysis estimated the risk of acquiring T. gondii by consuming raw or undercooked meat, regardless of which animal species are eaten. Using a random-effect model, crude and adjusted pooled measures of association (risk and odds ratio) were estimated according to study design (cohort, case-control, and cross-sectional studies). The meta-analysis included measures of heterogeneity as well as quality rating scales for each study design. Our results suggest that individuals who eat raw or undercooked meat have, respectively, 1.2-1.3 times the risk and 1.7-3.0 times the odds of T. gondii infection compared to those who thoroughly cook meat, regardless of the animal species they consume. These results align with the current understanding that adequately cooking meat inactivates the parasite and decreases the risk of transmission. Seroprevalence ranged from 1.3% to 88.6%, while the proportion of individuals eating raw or undercooked meat fluctuated from 0.7% to 98.3% across the studies in the meta-analysis. These numbers reflect various preferences with regard to eating meat (i.e., eating tartar, sausages, or salamis) as well as individual, cultural and religious food habits, and personal awareness.

Understanding the Connections Between Dogs, Health and Inuit Through a Mixed-Methods Study.

Dogs have been an integral part of the Inuit social and cultural environment for generations, but their presence also generates public health risks such as bites and exposure to zoonotic diseases such as rabies. In Nunavik, Canada, some prevention and control interventions targeting dogs have been implemented but have not demonstrated their effectiveness in a long-term sustainable perspective. This study was conducted in one Inuit community of Nunavik and used mixed methods to get a better understanding of factors that affect human and dog health, dog-related risks for humans and perceptions of dogs in Inuit communities using an interdisciplinary perspective in line with the Ecohealth approach. Results unveiled different perceptions and practices between Inuit and non-Inuit members of the community with regard to dogs and highlighted the positive role of dogs and their importance for Inuit health and well-being. This study provides new knowledge that is crucial for the development of integrated, sustainable and culturally adapted solutions to both the mitigation of dog-related health risks and the reinforcement of health and wellness benefits of dogs for Inuit.