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Snakebite envenomation (SBE) is a neglected One Health issue that overwhelmingly affects people living in rural and impoverished regions of Africa and Asia. Information on SBE is scarce in Rwanda; thus, our objectives were to 1) describe the demographics of SBE patients seeking hospital care, 2) evaluate physician adherence to national treatment guidelines, and 3) assess availability of snake antivenom at hospitals in Rwanda. To achieve these goals, we obtained national data on animal bites/stings and visited every district and provincial hospital in Rwanda to obtain physical records of SBE patients treated in 2017 and 2018. Hospital pharmacies were assessed for antivenom availability. We identified snakes as the second leading cause of animal bites, after dogs, among patients who sought hospital care in 2017 and 2018. Of 363 SBE patients, the highest number of cases occurred among children (< 18 years; 32%) and young adults (18–30 years; 33%), females (61%), farmers (82%), and those living in Eastern Province (37%). Overall, physician adherence to treatment guidelines was 63%. Prescriptions of vitamin K and antivenom were low (4% and 13%, respectively), and only 8% of hospital pharmacies had antivenom in stock throughout the study period. The antivenom stocked was an Indian generic suited for Asian snakes. This minimum estimate of hospitalization cases does not include individuals who died in communities or sought care outside the formal sector. Our study highlights the need to map incidence, risk factors, and patient experiences to mitigate human–snake conflicts and improve patient outcomes.

Alveolar echinococcosis (AE) is a life-threatening parasitic disease caused by the zoonotic cestode Echinococcus multilocularis. Our goals were to confirm infection, identify species, and analyze biogeographical origin of metacestode tissues from a suspected human AE case in Saskatchewan, Canada. We conducted polymerase chain reaction (PCR) targeting the nad1 mitochondrial gene for E. multilocularis and the rrnS ribosomal RNA gene for E. granulosus and conducted haplotype analysis at the nad2 locus. Our analysis confirmed AE and indicated that sequences matched infected Saskatchewan coyotes and European E3/E4 haplotypes. The patient had no travel history outside North America. This suggests autochthonous transmission of a European-type strain.

The Government of Rwanda reported an outbreak of Rift Valley fever (RVF) in the Eastern Province in 2018. To respond to the outbreak, vaccination and education campaigns about the disease were carried out. Because RVF cases continue to be detected in Rwanda and the disease impacts livelihoods and health, accurate knowledge and communication are imperative. The objectives of this study were to evaluate knowledge and risk perceptions of RVF transmission among livestock farmers in Nyagatare District, Eastern Province, Rwanda, and to compare RVF knowledge, risk perceptions, and farming practices between male and female livestock farmers. This cross-sectional, quantitative study was conducted in selected sectors of Nyagatare District in the Eastern Province of Rwanda in June 2019. A 34-question survey was used to ask about demographics, livestock ownership, risk perceptions about zoonotic diseases and livestock management, RVF knowledge, preferred communication sources and information sharing strategies, and protective strategies for RVF mitigation while working with livestock. Livestock farmers were interviewed at three milk collection centers, two village meeting points, a farm cooperative meeting, and during door-to-door visits in villages. In total, 123 livestock farmers were interviewed. The survey found that most livestock farmers lacked knowledge about epizootic and zoonotic transmission of RVF, more male livestock farmers were familiar with RVF and risk mitigation strategies, and female livestock farmers are not viewed as reliable sources of information. Additionally, most livestock farmers had not vaccinated their animals against RVF despite past vaccination campaigns. Radio was the most popular communication channel. These findings show that RVF knowledge and information sharing are inadequate among livestock farmers in Eastern Province. Therefore, vaccination and education campaigns may need to be reevaluated within the context of these trends in order to prepare for future RVF outbreaks., Author summary This study was conducted in order to evaluate RVF knowledge and awareness as well as communication and mitigation strategies among livestock farmers in Eastern Province, Rwanda. Rwanda declared an outbreak of RVF in 2018 and cases have continued to be detected. Thus, evaluating the status of knowledge, preventive strategies, and information sharing among livestock farmers is crucial in mitigating future outbreaks. Our team conducted a survey of knowledge, risk perceptions, mitigation strategies, and communication practices among livestock farmers from selected sectors within Nyagatare District and compared them between male and female livestock farmers in order to analyze gender-nuanced differences between these groups. Sectors were chosen for sampling based on their proximity to previous outbreak areas. Survey questionnaire results showed that knowledge and risk perceptions differed between male and female livestock farmers, and that they could be generally improved among all livestock farmers. Female livestock farmers and non-farming community members were viewed as unreliable sources of information which could impact information dissemination. Many farmers also reported that their livestock herds were not vaccinated for the disease despite previous vaccination campaigns. Communication strategies and information sources also differed between male and female livestock farmers, which highlights a need to consider gender in improving RVF vaccination and education campaign coverage. These findings pose implications for future community-based public health interventions as well as policy development for RVF control and mitigating future RVF outbreaks within Rwanda.

Background Malaria is a potentially fatal disease spread by the bites of Plasmodium-infected Anopheles mosquitoes. Despite long-term efforts to control malaria in Rwanda, malaria incidence increased from 48 to 403 cases/1000 individuals between 2012 and 2016. The diagnosis and treatment of malaria occurs at multiple levels, but the costs of these activities are not well understood. This research was conducted to estimate the direct medical costs incurred by the Ministry of Health in diagnosing and treating malaria in three districts of Rwanda in 2018. Methods A cross-sectional and retrospective costing analysis was conducted in three districts that represented low (5–200 cases per 1000 individuals), moderate (> 200–400 cases per 1000 individuals), and high (> 400 cases per 1000 individuals) endemicity regions. Data on malaria cases managed at three healthcare levels (community, health centre, district hospital) was obtained from national databases. The direct medical costs of cases per malaria severity (‘simple malaria’, ‘simple malaria with minor digestive symptoms’, and ‘severe malaria’) were calculated based on the minimum package of health services provided. Total costs for each of the three districts were also calculated. Results A total of 298,381 malaria cases were recorded in Burera, Kirehe, and Southern Kayonza districts in 2018. The average unit cost per case ranged from USD 1.36 (for simple malaria at the community level) to USD 92.80 (for severe malaria with cerebral complications at district hospitals). Simple malaria cases managed at health centres and district hospitals were more than two-fold (USD 2.99–USD 3.00) and more than eight-fold (USD 12.10–USD 12.12) higher, respectively, than those managed in the community (USD 1.36). Overall, the Ministry of Health incurred USD 645,647.68 in direct medical costs related to malaria management across the three districts in 2018. Changes in disease rates from different endemicity regions and costs of anti-malarial oral medications significantly impacted the study results. Conclusion In Rwanda, severe malaria results in much higher expenses compared to other malaria types. Prompt diagnosis and appropriate treatment are crucial to prevent the progression of simple malaria to severe malaria, to reduce Ministry of Health malaria expenditures, and to reduce community transmission.

Background Zoonotic taeniid cestodes are amongst the most important food-borne parasites affecting human health worldwide. Contamination of fresh produce with the eggs of Echinococcus granulosus (s.l.), Echinococcus multilocularis, and some Taenia species pose a potential food safety risk. However, very few studies have attempted to investigate the potential contamination of fresh produce with taeniid eggs and the available methods are not standardized for this purpose. Established protocols do exist for testing leafy greens and berries for contamination with protozoan parasites and are used in national surveillance programmes. This methodology could be suitable for the detection of taeniids. The objective of this project was to develop and standardize a sensitive and reliable method to detect contamination of leafy greens and berries with eggs of zoonotic taeniids and to differentiate between E. multilocularis, E. granulosus (s.l.) and Taenia spp. Methods We compared the efficacy of different wash solutions to remove Taenia spp. eggs from spiked produce, assessed two DNA extraction kits for their performance on Taenia spp. eggs, and adapted a published conventional multiplex PCR into a real-time PCR with fluorescence melting curve analysis (MCA) that was optimized for use on produce washes. Analytical specificity of this protocol was assessed using non-spiked produce washes as well as a variety of other potentially contaminating parasites. Results The protocol as established in this study had an analytical sensitivity of detecting five eggs per spiked sample for both romaine lettuce and strawberries. Unequivocal identification of E. multilocularis, E. granulosus (s.l.) and Taenia spp. was possible through MCA. Amplicon sequencing allowed identification of Taenia to the species level. The real-time PCR also amplified DNA from Dicrocoelium sp., but with a clearly discernable melting curve profile. Conclusion The new protocol for screening produce for taeniid contamination was highly sensitive. Melting curve analysis and the possibility of amplicon sequencing made this assay very specific. Once further validated, this method could be employed for surveillance of produce for contamination with taeniid parasites to assess potential risks for consumers.

In Vietnam, pigs and poultry are predominantly produced by small-scale farmers, creating challenges for zoonotic disease management. The objective of this study was to characterize practices related to livestock and manure management and to measure association with 3 self-reported health symptoms (coughing, fever, and diarrhea/nausea/vomiting) in a region currently undergoing health transitions. We analyzed cross-sectional survey data collected from a subset (N = 5520) of the Chi Linh Health and Demographic Surveillance System cohort in Chi Linh district, Vietnam. Bivariate analyses indicated that female gender was a significant risk factor for all 3 health symptoms, whereas age (≥60 years), suburban living, low education level, and household wealth were risk factors for 2 symptoms. Overall, we found no indication that biogas production or exposure to livestock and manure adversely affected human health. Efforts to control zoonotic disease transmission should prioritize utilization of veterinarians, enhanced farm biosecurity, and improvements to commune drinking water/wastewater infrastructure.

Gastrointestinal parasites have diverse life cycles that can involve people, animals, and the environment (e.g., water and soil), demonstrating the utility of One Health frameworks in characterizing infection risk. Kosumpee Forest Park (Thailand) is home to a dense population of long-tailed macaques (Macaca fascicularis) that frequently interact with tourists and local residents. Our study investigated the presence of zoonotic parasites, and barriers to healthy coexistence by conducting stool analysis on macaques (N = 102) and people (N = 115), and by examining risk factors for infection with a household questionnaire (N = 95). Overall, 44% of macaques and 12% of people were infected with one or more gastrointestinal helminths, including Strongyloides spp., Ascaris spp., and Trichuris sp. An adults-only generalized linear mixed model identified three factors significantly associated with human infection: household size, occupational exposure, and contact with macaque feces at home. Participants identified both advantages and disadvantages to living in close contact with macaques, suggesting that interventions to improve human and animal health in Kosumpee Forest Park would be welcome.

Dog-related human injuries affect public safety and animal welfare, and occur more frequently in rural, remote, and Indigenous communities than in urban centres in Canada. Little work has been done to identify the perspectives of those people most heavily affected by this issue or to report successful dog management programs. This project was undertaken by veterinarians and public health workers with the goal of documenting First Nations perspectives on dogs, and educating other rural health workers about introducing animal management services to Indigenous communities. We recruited 10-14 residents and healthcare workers from three First Nations to take dog-related photos in their communities and participate in group interviews during the summer of 2014. Audiovisual data were synthesised into four digital stories exploring the following aspects of participant relationships with community dogs: (1) Spay/neuter clinics; (2) Role of the dog (past and present); (3) Human-animal bond; and (4) Healthy dogs as a part of healthy communities. These videos document changes in dog husbandry behaviour, new acceptance of spay/neuter, three-way knowledge transfer between residents, researchers, and policy makers, and an overall desire to sustain the positive outcomes of the pilot dog management project. This work highlights cultural beliefs and success strategies that might guide other programs providing veterinary services in First Nations communities.

Free-roaming dog populations are a global concern for animal and human health including transmission of infectious disease (e.g. rabies, distemper and parasites), dog bite injuries/mortalities, animal welfare and adverse effects on wildlife. In Saskatchewan (SK), Canada, veterinary care is difficult to access in the remote and sparsely inhabited northern half of the province, where the population is predominately Indigenous. Even where veterinary clinics are readily available, there are important barriers such as cost, lack of transportation, unique cultural perspectives on dog husbandry and perceived need for veterinary care. We report the effects of introducing a community action plan designed to improve animal and human health, increase animal health literacy and benefit community well-being in two Indigenous communities where a dog-related child fatality recently occurred. Initial door-to-door dog demographic surveys indicated that most dogs were sexually intact (92% of 382 dogs), and few had ever been vaccinated (6%) or dewormed (6%). Approximately three animal-related injuries requiring medical care were reported in the communities per 1000 persons per year (95% CL: 1.6-6.6), and approximately 86% of 145 environmentally collected dog faecal samples contained parasites, far above levels reported in other urban or rural settings in SK. Following two subsidized spay/neuter clinics and active rehoming of dogs, parasite levels in dog faeces decreased significantly (P < 0.001), and important changes were observed in the dog demographic profile. This project demonstrates the importance of engaging people using familiar, local resources and taking a community specific approach. As well, it highlights the value of integrated, cross-jurisdictional cooperation, utilizing the resources of university researchers, veterinary personnel, public health, environmental health and community-based advocates to work together to solve complex issues in One Health. On-going surveillance on dog bites, parasite levels and dog demographics are needed to measure the long-term sustainability of benefits to dog, human and wildlife health.

Although surveillance is limited, indigenous residents at latitudes ranging from 53 to 73°N in Canada appear to have a higher occurrence of infection with some zoonotic parasites than the general population. Conversely, they are relatively naïve to other zoonotic parasites that have previously been unable to establish at northern latitudes. For those parasites that circulate among dogs, wildlife, and people, potential risk factors in the North include limited availability of veterinary services, presence of free-roaming dog populations, and consumption of locally harvested fish and wildlife. These regions are also experiencing some of the greatest impacts of climate change in North America, including increased temperature, precipitation, and frequency and severity of extreme weather. We review the current taxonomy, genetic diversity, host and geographic distributions, epidemiology and risk factors for 3 genera of helminths (Diphyllobothrium spp., Echinococcus spp., and Toxocara sp.) in Canada's North in order to identify climate-sensitive aspects of their ecology. Free-living stages of parasitic zoonoses endemic in the Arctic (such as Diphyllobothrium dendriticum, the cervid strain of Echinococcus granulosus, and Arctic strains of Echinococcus multilocularis) will experience trade-offs between enhanced survival under wetter conditions and increased mortality under warmer conditions. Climate change might also lead to the introduction and establishment in the Arctic of parasitic zoonoses previously restricted to the sub-Arctic, such as Diphyllobothrium latum, Toxocara canis, and the prairie strain of E. multilocularis. Molecular techniques applied in broad geographic surveys are needed to address critical knowledge gaps in the geographic distribution, genetic diversity, and public health significance of zoonotic helminths already in the circumpolar North, and to determine the current barriers to range expansion of temperate-adapted parasites into the North. Dogs will continue to play important roles in the North, including that of a "bridging" host between sylvatic cycles and human communities. In a warming north, increased opportunities for business, agriculture, and tourism favor importation of dogs and their parasites into a newly suitable environment. Collaborations among veterinarians, public health personnel, and policy-makers are needed to enhance surveillance and mitigate for dog-transmitted parasitic zoonoses in a changing North.

Zoonotic Echinococcus spp. cestodes (E. canadensis and E. multilocularis) infect domestic animals, wildlife, and people in regions of Canada and the USA. We recovered and quantified Echinococcus spp. cestodes from 22 of 307 intestinal tracts of wild canids (23 wolves, 100 coyotes, 184 red and arctic foxes) in the state of Maine and the province of Québec. We identified the species and genotypes of three Echinococcus spp. cestodes per infected animal by sequencing mitochondrial DNA at two loci. We further confirmed the absence of E. multilocularis by extracting DNA from pools of all cestodes from each animal and running a duplex PCR capable of distinguishing the two species. We detected E. canadensis (G8 and G10), but not E. multilocularis, which is emerging as an important human and animal health concern in adjacent regions. Prevalence and median intensity of E. canadensis was higher in wolves (35%, 460) than coyotes (14%, 358). This parasite has historically been absent in Atlantic regions of North America, where suitable intermediate hosts, but not wolves, are present. Our study suggests that coyotes are serving as sylvatic definitive hosts for E. canadensis in Atlantic regions, and this may facilitate eastward range expansion of E. canadensis in the USA and Canada. As well, compared to wolves, coyotes are more likely to contaminate urban green spaces and peri-urban environments with zoonotic parasites., Author summary Echinococcosis is a zoonosis caused by ingestion of tapeworm eggs in feces of wild or domestic canids (e.g. foxes, wolves, coyotes, and dogs). In North America, the number of new human echinococcosis cases reported annually is low; however, recent reports of these parasites in unusual presentations, in new locations, and in wildlife near urban areas have caused renewed interest by veterinary and human health professionals. In a cross-border collaboration, we examined the intestines of wolves (Canis lupus), coyotes (C. latrans) and foxes (Vulpes vulpes, V. lagopus) trapped in Québec (Canada) and neighboring Maine (USA), using genetic tools to identify Echinococcus tapeworms. We did not detect E. multilocularis, a serious threat to human health that has recently emerged in southern Ontario. We did identify E. canadensis in wolves and coyotes, in both Quebec and Maine. The presence of this parasite in coyotes is especially concerning because coyotes are more likely to come into close proximity with human communities. This information is relevant to veterinarians who should promote regular fecal examination and/or deworming of high risk dogs (dogs that scavenge or hunt cervids, such as moose), to physicians who might encounter this relatively rare disease, and to public health agencies who should promote surveillance and develop precautions for high risk people.

Human excreta is a low cost source of nutrients vital to plant growth, but also a source of pathogens transmissible to people and animals. We investigated the cost-savings and infection risk of soil transmitted helminths (STHs) in four scenarios where farmers used either inorganic fertilizer or fresh/composted human excreta supplemented by inorganic fertilizer to meet the nutrient requirements of rice paddies in the Red River Delta, Vietnam. Our study included two main components: 1) a risk estimate of STH infection for farmers who handle fresh excreta, determined by systematic review and meta-analysis; and 2) a cost estimate of fertilizing rice paddies, determined by nutrient assessment of excreta, a retailer survey of inorganic fertilizer costs, and a literature review to identify region-specific inputs. Our findings suggest that farmers who reuse fresh excreta are 1.24 (95% CI: 1.13–1.37, p-value, Author summary Each year, hundreds of millions of people worldwide are infected with intestinal worms spread by contaminated soil, also known as soil transmitted helminths (STHs). These worms are most common in tropical climates in areas lacking good hygiene and sanitation, and negatively impact child development, quality of life, and economic wellbeing. Reuse of human excreta for fertilizer is a common practice in many low to middle income countries because farmers require a low cost source of nutrients to grow food crops eaten by people and animals. Excreta can contain microbes, such as STHs, that cause disease in people; however, composting is a known method of killing STHs. Therefore, our goal was to determine if Vietnamese rice farmers involved in this practice are at higher risk of STH infection, and to calculate the amount of money saved by farmers composting for different lengths of time, and supplementing with various commercial fertilizers. We suggest that farmers compost excreta for six months to reduce disease exposure and optimize household savings. Optimizing practices to improve food production and protect farmer health is critical for poverty alleviation in low to middle income countries.

Toxoplasma gondii and Toxocara spp. are zoonotic parasites with potentially severe long-term consequences for those infected. We estimated incidence and investigated distribution, risk factors, and costs associated with these parasites by examining hospital discharge abstracts submitted to the Canadian Institute for Health Information (2002-2011). Annual incidence of serious toxoplasmosis and toxocariasis was 0.257 (95% confidence interval [CI]: 0.254-0.260) and 0.010 (95% CI: 0.007-0.014) cases per 100,000 persons, respectively. Median annual health-care costs per serious case of congenital, adult-acquired, and human immunodeficiency virus (HIV)-associated toxoplasmosis were $1,971, $763, and $5,744, respectively, with an overall cost of C$1,686,860 annually (2015 Canadian dollars). However, the total economic burden of toxoplasmosis is likely much higher than these direct health-care cost estimates. HIV was reported as a comorbidity in 40% of toxoplasmosis cases and accounted for over half of direct health-care costs associated with clinical toxoplasmosis. A One Health approach, integrating physician and veterinary input, is recommended for increasing public awareness and decreasing the economic burden of these preventable zoonoses.

The aim of our Opinion article [1] was to stimulate discussion on the taxonomic status of the G6, G7, G8, and G10 genotypes of Echinococcus granulosus, and we therefore welcome the letter from Nakao et al. (2015) [2]. They make two main points, one concerning the separation of the G8 and G10 (cervid) genotypes, and one concerning the nomenclature of the G6/G7 (camel and pig) genotypes. With both these points there are aspects which we can agree upon, but others about which we must disagree. However, the areas of disagreement can be settled empirically with further data, and we hope that such data will be forthcoming soon.

Echinococcosis is a rare but endemic condition in people in Canada, caused by a zoonotic cestode for which the source of human infection is ingestion of parasite eggs shed by canids. The objectives of this study were to identify risk factors associated with infection and to measure the cost-utility of introducing an echinococcosis prevention program in a rural area. We analyzed human case reports submitted to the Canadian Institutes for Health Information between 2002 and 2011. Over this 10 year period, there were 48 cases associated with E. granulosus/E. canadensis, 16 with E. multilocularis, and 251 cases of echinococcosis for which species was not identified (total 315 cases). Nationally, annual incidence of echinococcosis was 0.14 cases per 100 000 people, which is likely an underestimate due to under-diagnosis and under-reporting. Risk factors for echinococcosis included female gender, age (>65 years), and residing in one of the northern territories (Nunavut, Yukon, or Northwest Territories). The average cost of treating a case of cystic echinococcosis in Canada was $8,842 CAD. Cost-utility analysis revealed that dosing dogs with praziquantel (a cestocide) at six week intervals to control cystic echinococcosis is not currently cost-effective at a threshold of $20,000-100,000 per Quality Adjusted Life Year (QALY) gained, even in a health region with the highest incidence rate in Canada ($666,978 -755,051 per QALY gained). However, threshold analysis demonstrated that the program may become cost-saving at an echinococcosis incidence of 13-85 cases per 100,000 people and therefore, even one additional CE case in a community of 9000 people could result in the monetary benefits of the program outweighing costs., Author Summary In Canada, Echinococcus spp. tapeworms cycle primarily among wildlife hosts. People are infected with this parasite when they accidentally consume microscopic eggs spread by canids (e.g. dogs, wolves, coyotes, and foxes), and develop larval cysts, often in the liver or lungs. Echinococcosis can be a life-threatening medical condition with long-term health consequences and can be an economic burden for infected individuals and for the public health system. We analysed national health records to measure echinococcosis incidence and risk factors in Canada, and then used this information to determine if a program that facilitated dog deworming to prevent human infection might be economically feasible. Our model suggested that treating infected individuals is currently less expensive than preventing infection, even in the highest risk regions of Canada. However, deworming dogs might be feasible in small rural communities where at least one case was identified. Furthermore, the prevention program has many add-on benefits that contribute to overall community health, but are not measured by our model.

Fecal samples from wild and domestic carnivores are routinely frozen for three days at -80°C to kill eggs of Echinococcus spp., following recommendations from the World Health Organization (WHO) and World Organization for Animal Health (OIE). This is done to decrease the risk of zoonotic infection with these pathogenic cestodes. In addition, it is often necessary to freeze fecal samples collected for research prior to batch processing by a limited number of personnel, especially large numbers of samples or those collected in remote locations. The effect of freezing on the recovery of endoparasite eggs, cysts and oocysts from fecal samples is not well documented, even in hosts for which veterinary diagnostic submissions are relatively common. In this study, fecal samples from naturally infected dogs and horses were split into four treatment groups: fresh; -80°C for 3 days; -20°C for 30 days; and -80°C for 3 days followed by -20°C for an additional 30 days. Temperatures and times were chosen to simulate diagnostic and research protocols currently in place. Helminth eggs and sporocysts of Sarcocystis spp. were counted using a quantitative double centrifugation sucrose fecal flotation (modified Stoll egg count). Repeated measures ANOVA was used to detect differences in egg/sporocyst counts between the treatment groups for Sarcocystis spp. sporocysts, taeniid eggs (Taenia and/or Echinococcus spp.), ascarid eggs (Parascaris equorum, Toxocara canis, Toxascaris leonina), and strongylid type eggs (Uncinaria stenocephala, and equine strongylids, most likely cyathostomins). Counts for P. equorum and strongylid type eggs (both equine and canine) decreased significantly following freezing. Post-freezing, some samples that had been positive on fresh examination became negative for Parascaris and strongylid eggs. This study suggests that protocols requiring freezing artificially lowers recovery of eggs of Parascaris and strongylid nematodes in fecal surveys; however, recovery rates for eggs of other helminth species as well as sporocysts of Sarcocystis spp. were relatively robust compared to the freshly tested fecal samples. This is reassuring for large scale fecal surveys needed for fecal egg count reduction analyses following treatment, and for surveillance in wildlife and remote human and animal populations.

SUMMARYEchinococcus species are important parasites of wildlife, domestic animals and people worldwide; however, little is known about the prevalence, intensity and genetic diversity of Echinococcus tapeworms in Canadian wildlife. Echinococcus tapeworms were harvested from the intestines of 42% of 93 wolves (Canis lupus) from five sampling regions in the Northwest Territories, Manitoba and Saskatchewan, and visually identified to genus level by microscopic examination. Genetic characterization was successful for tapeworms from 30 wolves, and identified both Echinococcus canadensis and Echinococcus multilocularis in all sampling locations. Mixed infections of E. canadensis/E. multilocularis, as well as the G8/G10 genotypes of E. canadensis were observed. These findings suggest that wolves may be an important definitive host for both parasite species in western Canada. This represents the first report of wolves naturally infected with E. multilocularis in North America, and of wolves harbouring mixed infections with multiple species and genotypes of Echinococcus. These observations provide important information regarding the distribution and diversity of zoonotic species of Echinococcus in western North America, and may be of interest from public health and wildlife conservation perspectives.

Zoonotic parasites are important causes of endemic and emerging human disease in northern North America and Greenland (the North), where prevalence of some parasites is higher than in the general North American population. The North today is in transition, facing increased resource extraction, globalisation of trade and travel, and rapid and accelerating environmental change. This comprehensive review addresses the diversity, distribution, ecology, epidemiology, and significance of nine zoonotic parasites in animal and human populations in the North. Based on a qualitative risk assessment with criteria heavily weighted for human health, these zoonotic parasites are ranked, in the order of decreasing importance, as follows: Echinococcus multilocularis, Toxoplasma gondii, Trichinella and Giardia, Echinococcus granulosus/canadensis and Cryptosporidium, Toxocara, anisakid nematodes, and diphyllobothriid cestodes. Recent and future trends in the importance of these parasites for human health in the North are explored. For example, the incidence of human exposure to endemic helminth zoonoses (e.g. Diphyllobothrium, Trichinella, and Echinococcus) appears to be declining, while water-borne protozoans such as Giardia, Cryptosporidium, and Toxoplasma may be emerging causes of human disease in a warming North. Parasites that undergo temperature-dependent development in the environment (such as Toxoplasma, ascarid and anisakid nematodes, and diphyllobothriid cestodes) will likely undergo accelerated development in endemic areas and temperate-adapted strains/species will move north, resulting in faunal shifts. Food-borne pathogens (e.g. Trichinella, Toxoplasma, anisakid nematodes, and diphyllobothriid cestodes) may be increasingly important as animal products are exported from the North and tourists, workers, and domestic animals enter the North. Finally, key needs are identified to better assess and mitigate risks associated with zoonotic parasites, including enhanced surveillance in animals and people, detection methods, and delivery and evaluation of veterinary and public health services.

We report the results of a joint human-animal health investigation in a Dene community in northern Saskatchewan, where residents harvest wildlife (including moose, bear, elk, and fish), live in close contact with free roaming dogs, and lack access to permanent veterinary services. Fecal analysis of owned and free-roaming dogs over two consecutive years (N = 92, 103) identified several parasites of public health concern, including Toxocara canis, Diphyllobothrium spp., Echinococcus/Taenia, Cryptosporidium spp. and Giardia spp. Administration of pyrantel pamoate to a subset of dogs (N = 122) in the community in the first year was followed by reduced shedding of T. canis and other roundworms in the second year, demonstrating the potential utility of canine de-worming as a public health intervention. Using direct agglutination tests with confirmatory indirect fluorescent antibody test, 21% of 47 dogs were sero-positive for exposure to Toxoplasma gondii. Using enzyme-linked immunosorbent assay (ELISA) sero-prevalence rates in 201 human volunteers were as follows: Toxoplasma gondii (14%), Echinococcus granulosus (48%), Toxocara canis (13%) and Trichinella spp. (16%). Overall 65% of participants were sero-positive for at least one parasite. A survey administered to volunteers indicated few associations between widely accepted risk factors for parasite exposure and serological status, emphasizing the importance of environmental transmission of these parasites through soil, food, and waterborne routes., Author Summary Parasites are ubiquitous, and while some parasitize only one host, others are capable of crossing species barriers. Zoonotic parasites move between animals and people, and in some cases cause significant veterinary, medical and/or public health problems. Such parasites may be more prevalent in areas where veterinary and medical services are scarce, and especially if sanitation infrastructure is suboptimal. Additional risk factors include reliance on country foods, proximity to pets that come in contact with wildlife, and eating undercooked or raw fish and game. We visited one northern Indigenous community over two consecutive years to determine the prevalence of internal parasites in dogs, as well as to demonstrate the effect of selective deworming on reducing environmental contamination by zoonotic parasites. In addition, we collected blood samples and administered surveys to human volunteers in order to explore the relationship between exposure to four zoonotic parasites and several widely accepted risk factors for exposure (e.g. pet ownership). Our findings indicate that levels of parasite exposure in this community were higher than similar studies conducted in other Canadian Indigenous communities. Public health interventions that utilize a one health strategy by integrating medical, veterinary and environmental expertise may be the most effective approach in reducing human and animal exposure to parasites in this community.