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Snakebite envenomation (SBE) is a serious medical condition with human, animal, and environmental factors driving occurrence. In Rwanda, the number of SBE cases reported by the medical system is far lower than regional estimates for SBE incidence, suggesting that victims might be seeking care outside of formal medical structures. Our goals were to describe circumstances surrounding snakebite and to explore experiences of snakebite victims in accessing treatment. For this qualitative study, our team recruited individuals bitten by snakes between 2013 and 2018, who sought care either from traditional healers (N = 40) or hospitals (N = 65). In-depth interviews based on a semi-structured interview guide were conducted by telephone in Kinyarwanda. Inductive thematic analysis was conducted by two team members. Our respondents reported similar environmental circumstances surrounding their snake encounters; namely, farm fields, roads, and their homes, as well as inadequate lighting. Unsafe First Aid practices, including burning/sucking/cutting the skin and tourniquet, were often performed immediately after bites. Respondents reported various reasons for seeking traditional or hospital care, such as perceived cost, distance, transportation, and especially, community beliefs and treatment outcomes of other victims. Respondents described envenomation of livestock as well as the sale of livestock to pay SBE-related medical expenses. Improving trust and use of formal medical services will require enhanced hospital delivery of high quality medical services for SBE through improved stocking of appropriate anti-venom and reduced delays during intake. Communities might also benefit from education campaigns that discourage unsafe First Aid practices and address the common misperception that physicians are not trained to treat SBE.

One Health is defined as the intersection and integration of knowledge regarding humans, animals, and the environment, yet as the One Health scientific literature expands, there is considerable heterogeneity of approach and quality of reporting in One Health studies. In addition, many researchers who publish such studies do not include or integrate data from all three domains of human, animal, and environmental health. This points to a critical need to unify guidelines for One Health studies. This report details the Checklist for One Health Epidemiological Reporting of Evidence (COHERE) to guide the design and publication format of future One Health studies. COHERE was developed by a core writing team and international expert review group that represents multiple disciplines, including human medicine, veterinary medicine, public health, allied professionals, clinical laboratory science, epidemiology, the social sciences, ecohealth and environmental health. The twin aims of the COHERE standards are to 1) improve the quality of reporting of observational or interventional epidemiological studies that collect and integrate data from humans, animals and/or vectors, and their environments; and 2) promote the concept that One Health studies should integrate knowledge from these three domains. The 19 standards in the COHERE checklist address descriptions of human populations, animal populations, environmental assessment, spatial and temporal relationships of data from the three domains, integration of analyses and interpretation, and inclusion of expertise in the research team from disciplines related to human health, animal health, and environmental health., Highlights • A Checklist for One Health Epidemiological Reporting of Evidence (COHERE) is proposed. • COHERE was developed by a core writing team and international expert review group. • The aim is to improve studies that report on data from humans, animals and the environment.

Zoonotic Echinococcus spp. cestodes are present in almost all circumpolar nations, and have historically posed a risk to health of indigenous as well as other northern residents. However, surveillance data on both alveolar (AE) and cystic (CE) echinococcosis remains incomplete throughout the circumpolar region: Russia, Fennoscandia, Iceland, Greenland, Canada and Alaska (USA). Prevalence of Echinococcus spp. varies considerably in definitive canid hosts, animal intermediate hosts and accidental hosts like humans. Yet despite the high prevalence reported in canids in some geographic locations, human AE and CE are much less common than in endemic Asian and central European countries. This paper explores knowledge gaps and future challenges posed by Echinococcus spp. in eight circumpolar countries, a region where rapid environmental and social change are rewriting the boundaries, transmission, and impact of many pathogens, including zoonotic Echinococcus spp.Genotypes G6, G8 and G10 of Echinococcus canadensis are causative agents of human CE and have been identified in sylvatic (wild animal) and synanthropic (ecological association with humans) cervid-canine life cycles in the following northern regions: Alaska and northern Canada - G8 and G10; northern Russia - G6, G8, G10; and Fennoscandia - G10 in Finland - with no recent reports from Norway or Sweden. Echinococcus multilocularis, which causes AE, has been identified in a sylvatic arvicoline rodent-canine lifecycle in Alaska, Canada, Russia, Sweden and Svalbard (Norway). Asian, Mongolian, European and North American strains of E. multilocularis are found in Russia, with the North American N1 strain predominating in the north. The N1 strain is also found in Alaska, as well as Svalbard, whilst Asian strains have been identified in western Alaska. Central North American (N2) strain and European-type strains of E. multilocularis are present in Canada. Typing of the strain in Sweden is still pending. Individual human cases of AE with N2 and European-type strains are reported in North America, as well as multiple cases with Asian strains in Russia and historically on St Lawrence Island, Alaska (although genotyping of human cases was not available at the time). Echinococcus spp. have not been detected in Greenland and have been eliminated from Iceland.The predominance of E. multilocularis N1 strain and E. canadensis genotypes, in regions with high prevalence in definitive hosts yet low incidence of human AE and CE, suggests that these genotypes have lower zoonotic potential and pathogenicity than European and Asian strains of E. multilocularis and livestock genotypes of E granulosus sensu stricto. The continued monitoring of the emergence of Echinococcus genotypes within definitive and intermediate hosts, as well as people, is needed to assess the impact on public health risk, since the introduction of other genotypes could have serious repercussions. Lastly, determining risk factors and source attribution for human cases, including the possibility of food and waterborne transmission and the likelihood of autochthonous transmission, remain challenges. Keywords: Alveolar echinococcosis, Arctic, Circumpolar, Cystic echinococcosis, Genotypes

The phylogenetic relationships of the G6, G7, G8, and G10 genotypes of Echinococcus granulosus are well defined, but their taxonomic status is currently unresolved. We apply an evolutionary species concept to infer that the G6 and G7 genotypes represent a single species that is different to both the G8 and G10 genotypes, and that the G8 and G10 genotypes are also on different evolutionary trajectories and, therefore, should be regarded as separate species. The names Echinococcus intermedius, Echinococcus canadensis, and Echinococcus borealis have been previously proposed for these three taxa (G6/7, G10 and G8, respectively) and we argue that it may be appropriate to resurrect these names. The correct delimitation and formal recognition of species of Echinococcus may have important veterinary and public health consequences.

Highlights • First large-scale survey of Echinococcus multilocularis of western and Arctic Canada. • Identified 17 polymorphisms in the NADH dehydrogenase subunit 1 (nad1) mitochondrial gene of Echinococcus multilocularis. • Analysis of a single mitochondrial gene across adult cestodes, larvae and eggs of Canadian Echinococcus multilocularis., Echinococcus multilocularis is a zoonotic cestode with a distribution encompassing the northern hemisphere that causes alveolar hydatid disease in people and other aberrant hosts. E.multilocularis is not genetically uniform across its distribution, which may have implications for zoonotic transmission and pathogenicity. Recent findings of a European-type haplotype of E. multilocularis in wildlife in one location in western Canada motivated a broader survey of the diversity of this parasite in wildlife from northern and western Canada. We obtained intact adult cestodes of E. multilocularis from the intestines of 41 wild canids (wolf – Canis lupus, coyote – Canis latrans, and red fox – Vulpes vulpes), taeniid eggs from 28 fecal samples from Arctic fox (Vulpes lagopus), and alveolar hydatid cysts from 39 potential rodent intermediate hosts. Upon sequencing a 370-nucelotide region of the NADH dehydrogenase subunit 1 (nad1) mitochondrial locus, 17 new haplotypes were identified. This constitutes a much higher diversity than expected, as only two genotypes (European and an Asian/North American) had previously been identified using this locus. The European-type strain, recently introduced, may be widespread in wildlife within western Canada, possibly related to the large home ranges and wide dispersal range of wild canids. This study increased understanding of the biogeographic distribution, prevalence and genetic differences of a globally important pathogenic cestode in northern and western Canada.

Echinococcus multilocularis is a zoonotic cestode of canid definitive hosts that is emerging as a parasite of medical and veterinary concern in regions of North America, Europe and Asia. Infection with the metacestode stage (alveolar echinococcosis – AE) is life-threatening, especially for patients who reside in low resource countries and lack access to modern diagnostic tests and treatments. The overall objectives of this One Health review were to systematically describe the diagnostic tests currently employed in endemic countries to detect E. multilocularis in people, canids and the environment, and to report the test characteristics of new diagnostic techniques for population surveillance. In this systematic review of English and Chinese language databases, we identified 92 primary records of E. multilocularis surveillance in canids (N = 75), humans (N = 20) and/or the environment (food, soil; N = 3) and 12 grey literature records that reported E. multilocularis surveillance or health systems protocols between 2008 and 2018. Surveillance for E. multilocularis was conducted using a broad range of combined morphological, molecular, immunological and imaging techniques. Nine studies reporting diagnostic evaluations for cestode or metacestode detection were identified, including studies on copro-antigen ELISA, copro-PCR, intestinal examination, Western Blot, magnetic capture RT-PCR and immunochromatography. Our dataset includes prevalence estimates for E. multilocularis in canids, people, or environment in 27 of the 43 endemic countries and reports data gaps in surveillance, laboratory methods, and diagnostic sensitivity. International consensus on gold standard diagnostic techniques and harmonization of human, canid and environmental surveillance data across political boundaries are needed to comprehensively assess the global burden and distribution of this parasite., Highlights • Reports of AE prevalence were found most often from China, France, Poland and Canada. • Accuracy of new molecular, immunological, and post-mortem tests is described. • Surveillance across political boundaries and hosts is needed to estimate true burden.

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.