Wildlife parasites in a One Health world

Global prevalence and risk factors associated with Toxoplasma gondii infection in wild birds: A systematic review and meta-analysis

A systematic review and meta-analysis were performed to identify the global prevalence and factors associated with Toxoplasma gondii infection in wild birds. Six bibliographic databases (Chinese National Knowledge Infrastructure, VIP Chinese Journal Database, Wanfang Data, PubMed, Web of science and ScienceDirect) were searched from inception to February 2023. The search yielded 1220 records of which 659 articles underwent full-text evaluation, which identified 49 eligible articles and 16,030 wild bird samples that were included in the meta-analysis. The estimated pooled global prevalence of T. gondii infection in wild birds was 16.6%. Out of the variables tested, publication year after 2020 and climate type were significantly associated with T. gondii infection (P<0.01). Our data indicate that the prevalence of T. gondii in wild birds can be influenced by epidemiological variables. Further research is needed to identify the biological, environmental, anthropogenic, and geographical risk factors which impact the ecology and prevalence of T. gondii in wild birds.

Toxoplasma gondii in a Remote Subsistence Hunting-Based Indigenous Community of the Peruvian Amazon

Toxoplasma gondii is a ubiquitous zoonotic protozoan parasite that infects a wide variety range of warm-blooded animals. This study describes the epidemiological scenario of T. gondii in an indigenous community that relies on subsistence hunting in a well-conserved and isolated area of the Peruvian Amazon. The high seropositivity against T. gondii in humans (83.3% IgG and 6.1% IgM), wild mammals (30.45%, 17 species), peri-domestic rodents (10.0% Rattus sp.), and domestic animals (94.1% dogs and 100% cats) indicates the existence of a sylvatic cycle in the community under study. Individual age was found to be positively associated with IgG detection against T. gondii but not with IgM. It is estimated that each family consumed 5.67 infected animals per year with terrestrial species having higher infective rates than arboreal species. The main risk factors included improper handling and cooking of wild meat, poor hygiene practices, and feeding uncooked offal to domestic animals. This scenario results in a continuous process of infection and reinfection within the indigenous community with cats, dogs, and peri-domestic animals becoming infected through the ingestion of infected raw viscera. Our results emphasize the need to promote safe food handling practices and disposal of waste materials from hunted animals in such communities.

Exploring the diversity of tick-borne pathogens: The case of bacteria (Anaplasma, Rickettsia, Coxiella and Borrelia) protozoa (Babesia and Theileria) and viruses (Orthonairovirus, tick-borne encephalitis virus and louping ill virus) in the European continent

Ticks are the main vectors for the transmission of bacterial, protist and viral pathogens in Europe affecting wildlife and domestic animals. However, some of them are zoonotic and can cause serious, sometimes fatal, problems in human health. A systematic review in PubMed/MEDLINE database was conducted to determine the spatial distribution and host and tick species ranges of a selection of tick-borne bacteria (Anaplasma spp., Borrelia spp., Coxiella spp., and Rickettsia spp.), protists (Babesia spp. and Theileria spp.), and viruses (Orthonairovirus, and flaviviruses tick-borne encephalitis virus and louping ill virus) on the European continent in a five-year period (November 2017 - November 2022). Only studies using PCR methods were selected, retrieving a total of 429 articles. Overall, up to 85 species of the selected tick-borne pathogens were reported from 36 European countries, and Anaplasma spp. was described in 37% (159/429) of the articles, followed by Babesia spp. (34%, 148/429), Borrelia spp. (34%, 147/429), Rickettsia spp. (33%, 142/429), Theileria spp. (11%, 47/429), tick-borne flaviviruses (9%, 37/429), Orthonairovirus (7%, 28/429) and Coxiella spp. (5%, 20/429). Host and tick ranges included 97 and 50 species, respectively. The highest tick-borne pathogen diversity was detected in domestic animals, and 12 species were shared between humans, wildlife, and domestic hosts, highlighting the following zoonotic species: Anaplasma phagocytophilum, Babesia divergens, Babesia microti, Borrelia afzelii, Borrelia burgdorferi s.s., Borrelia garinii, Borrelia miyamotoi, Crimean-Congo hemorrhagic fever virus, Coxiella burnetii, Rickettsia monacensis and tick-borne encephalitis virus. These results contribute to the implementation of effective interventions for the surveillance and control of tick-borne diseases.

Local thermal adaptation and local temperature regimes drive the performance of a parasitic helminth under climate change: The case of Marshallagia marshalli from wild ungulates

Across a species' range, populations are exposed to their local thermal environments, which on an evolutionary scale, may cause adaptative differences among populations. Helminths often have broad geographic ranges and temperature-sensitive life stages but little is known about whether and how local thermal adaptation can influence their response to climate change. We studied the thermal responses of the free-living stages of Marshallagia marshalli, a parasitic nematode of wild ungulates, along a latitudinal gradient. We first determine its distribution in wild sheep species in North America. Then we cultured M. marshalli eggs from different locations at temperatures from 5 to 38°C. We fit performance curves based on the metabolic theory of ecology to determine whether development and mortality showed evidence of local thermal adaptation. We used parameter estimates in life-cycle-based host-parasite models to understand how local thermal responses may influence parasite performance under general and location-specific climate-change projections. We found that M. marshalli has a wide latitudinal and host range, infecting wild sheep species from New Mexico to Yukon. Increases in mortality and development time at higher temperatures were most evident for isolates from northern locations. Accounting for location-specific parasite parameters primarily influenced the magnitude of climate change parasite performance, while accounting for location-specific climates primarily influenced the phenology of parasite performance. Despite differences in development and mortality among M. marshalli populations, when using site-specific climate change projections, there was a similar magnitude of impact on the relative performance of M. marshalli among populations. Climate change is predicted to decrease the expected lifetime reproductive output of M. marshalli in all populations while delaying its seasonal peak by approximately 1 month. Our research suggests that accurate projections of the impacts of climate change on broadly distributed species need to consider local adaptations of organisms together with local temperature profiles and climate projections.

A new multiplexed magnetic capture-Droplet digital PCR tool for monitoring wildlife population health and pathogen surveillance

Anthropogenic stressors are exacerbating the emergence and spread of pathogens worldwide. In regions like the Arctic, where ecosystems are particularly susceptible, marked changes are predicted in regional diversity, intensity, and patterns of infectious diseases. To understand such rapidly changing host-pathogen dynamics and mitigate the impacts of novel pathogens, we need sensitive disease surveillance tools. We developed and validated a novel multiplexed, magnetic capture, and ddPCR tool for the surveillance of multiple pathogens in polar bears, a sentinel species that is considered susceptible to climate change and other stressors with a pan-Arctic distribution. Through sequence-specific magnetic capture, we concentrated five target template sequences from three zoonotic bacteria (Erysipelothrix rhusiopathiae, Francisella tularensis, and Mycobacterium tuberculosis complex) and two parasitic (Toxoplasma gondii and Trichinella spp.) pathogens from large quantities (<100 g) of host tissue. We then designed and validated two multiplexed probe-based ddPCR assays for the amplification and detection of the low-concentration target DNA. Validations used 48 polar bear tissues (muscle and liver). We detected 14, 1, 3, 4, and 22 tissue positives for E. rhusiopathiae, F. tularensis, M. tuberculosis complex, T. gondii, and Trichinella spp., respectively. These multiplexed assays offer a rapid, specific tool for quantifying and monitoring the changing geographical and host distributions of pathogens relevant to human and animal health.

Giardia and Cryptosporidium in resident wildlife species in Arctic Alaska

Giardia and Cryptosporidium are zoonotic protozoan parasites that can infect humans and other taxa, including wildlife, often causing gastrointestinal illness. Both have been identified as One Health priorities in the Arctic, where climate change is expected to influence the distribution of many wildlife and zoonotic diseases, but little is known about their prevalence in local wildlife. To help fill information gaps, we collected fecal samples from four wildlife species that occur seasonally on the northern Alaska coastline or in nearshore marine waters-Arctic fox (Vulpes lagopus), polar bear (Ursus maritimus), Pacific walrus (Odobenus rosmarus divergens), and caribou (Rangifer tarandus)-and used immunofluorescence assays to screen for Giardia cysts and Cryptosporidium oocysts. We detected Giardia cysts in 18.3% and Cryptosporidium oocysts in 16.5% of Arctic foxes (n = 109), suggesting that foxes may be potentially important hosts in this region. We also detected Giardia cysts in a single polar bear (12.5%; n = 8), which to our knowledge represents the first such report for this species. Neither parasite was detected in walruses or caribou.

Prevalence of Toxoplasma gondii in Galapagos birds: Inference of risk factors associated with diet

Toxoplasma gondii is a zoonotic intracellular parasite of particular concern in the conservation of wildlife due to its ability to infect all homeotherms and potentially cause acute fatal disease in naive species. In the Galapagos (Ecuador), an archipelago composed of more than a hundred islets and islands, the presence of T. gondii can be attributed to human-introduced domestic cats, but little is known about its transmission in wildlife populations. We compared the prevalence of antibodies against T. gondii in sympatric Galapagos wild bird species that differ in diet and contact with oocyst-contaminated soil to determine the relative importance of trophic habits as an exposure factor. Plasma samples were obtained from 163 land birds inhabiting Santa Cruz, one of the cat-inhabited islands, and from 187 seabirds breeding in cat-free surrounding islands (Daphne Major, North Seymour, and South Plaza). These samples were tested for the presence of T. gondii antibodies using the modified agglutination test (MAT ≥ 1:10). All seven species of land birds and 4/6 species of seabirds presented seropositive results. All great frigatebirds (Fregata minor) (N = 25) and swallow-tailed gulls (Creagrus furcatus) (N = 23) were seronegative. Prevalence ranged from 13% in Nazca boobies (Sula granti) to 100% in Galapagos mockingbirds (Mimus parvulus). It decreased from occasional carnivores (63.43%) to granivores-insectivores (26.22%), and strict piscivores (14.62%). These results indicate that the consumption of tissue cysts poses the highest risk of exposure to T. gondii for Galapagos birds, followed by the ingestion of plants and insects contaminated by oocysts as important transmission pathways.

Cystic echinococcosis in Iceland: a brief history and genetic analysis of a 46-year-old Echinococcus isolate collected prior to the eradication of this zoonotic disease

Cystic echinococcosis (CE) is considered the most severe parasitic disease that ever affected the human population in Iceland. Before the start of eradication campaign in the 1860s, Iceland was a country with very high prevalence of human CE, with approximately every fifth person infected. Eradication of CE from Iceland by 1979 was a huge success story and served as a leading example for other countries on how to combat such a severe One Health problem. However, there is no genetic information on Echinococcus parasites before eradication. Here, we reveal the genetic identity for one of the last Echinococcus isolates in Iceland, obtained from a sheep 46 years ago (1977). We sequenced a large portion of the mitochondrial genome (8141 bp) and identified the isolate as Echinococcus granulosus sensu stricto genotype G1. As G1 is known to be highly infective genotype to humans, it may partly explain why such a large proportion of human population in Iceland was infected at a time . The study demonstrates that decades-old samples hold significant potential to uncover genetic identities of parasites in the past.

Filarial infections in lemurs: Evidence for a wide geographical distribution and low host specificity among lemur species

The relevance of emerging infectious diseases continues to grow worldwide as human activities increasingly extend into formerly remote natural areas. This is particularly noticeable on the island of Madagascar. As closest relatives to humans on the island, lemurs are of particular relevance as a potential origin of zoonotic pathogen spillover. Knowledge of pathogens circulating in lemur populations is, however, very poor. Particularly little is known about lemur hemoparasites. To infer host range, ecological and geographic spread of the recently described hemoparasitic nematode Lemurfilaria lemuris in northwestern Madagascar, a total of 942 individuals of two mouse lemur species (Microcebus murinus [n = 207] and Microcebus ravelobensis [n = 433]) and two rodent species (the endemic Eliurus myoxinus [n = 118] and the invasive Rattus rattus [n = 184]) were captured in two fragmented forest landscapes (Ankarafantsika National Park and Mariarano Classified Forest) in northwestern Madagascar for blood sample examination. No protozoan hemoparasites were detected by microscopic blood smear screening. Microfilaria were present in 1.0% (2/207) of M. murinus and 2.1% (9/433) of M. ravelobensis blood samples but not in rodent samples. Internal transcribed spacer 1 (ITS-1) sequences were identical to an unnamed Onchocercidae species previously described to infect a larger lemur species, Propithecus verreauxi, about 650 km further south. In contrast to expectations, L. lemuris was not detected. The finding of a pathogen in a distantly related host species, at a considerable geographic distance from the location of its original detection, instead of a microfilaria species previously described for one of the studied host species in the same region, illustrates our low level of knowledge of lemur hemoparasites, their host ranges, distribution, modes of transmission, and their zoonotic potential. Our findings shall stimulate new research that will be of relevance for both conservation medicine and human epidemiology.

Seroprevalence and associated risk factors of Toxoplasma gondii infection among slaughterhouse workers in Yangon Region, Myanmar: A cross-sectional study

BACKGROUND

Toxoplasmosis, having the significant consequences affecting mortality and quality of life, is still prevalent in various places throughout the world. The major gap in surveillance for Toxoplasma gondii infection among high-risk population, slaughterhouse workers, is an obstacle for the effective policies formulation to reduce the burden of toxoplasmosis in Myanmar. Therefore, this study aimed to assess the seroprevalence of toxoplasmosis and associated factors of seropositivity among slaughterhouse workers in Yangon Region, Myanmar.

METHODS

A cross-sectional study that was conducted from June to November 2020 included 139 slaughterhouse workers involving at five main slaughterhouses under Yangon City Development Committee, Myanmar. The presence of IgG and IgM anti-T. gondii antibodies in serum was detected using the OnSite Toxo IgG/IgM Combo Rapid Test. A face-to-face interview was also performed using pretested structured questionnaires to obtain the detail histories: sociodemographic characteristics, level of knowledge, occupational factors, and environmental factors related to T. gondii infection. Bivariate logistic regression was used to determine the factors associated with T. gondii infection.

RESULTS

Of all participants, the overall seroprevalence of anti-T. gondii was 43.9% (95% CI: 35.5-52.5%), of whom 98.4% (95% CI: 91.2-100.0%) were reactive only for IgG antibody and 1.6% (95% CI: 0.0-8.8%) were reactive for IgG and IgM antibodies. The significant factors associated with the seropositivity of T. gondii antibodies were blood transfusion history (OR: 5.74, 95% CI: 1.17-28.09), low level of knowledge (OR: 2.91, 95% CI: 1.46-5.83), contact with animal organs, muscles or blood (OR: 14.29, 95% CI: 1.83-111.51), and animals most frequently slaughtered (cattle) (OR: 3.22, 95% CI: 1.16-8.93).

CONCLUSIONS

A high seroprevalence of toxoplasmosis was detected among slaughterhouse workers in Yangon Region and it raises a significant public health concern. Therefore, providing health education regarding toxoplasmosis, enforcement of personal hygiene practices in workplaces, the establishment of training for occupational hygiene, and commencement of the risk assessment and serological screening for toxoplasmosis are crucial to curtail the prevalence of T. gondii infection among slaughterhouse workers.

Serological Evidence of Orthopoxvirus Infection in Neotropical Primates in Brazil

The genus Orthopoxvirus (OPXV) of the family Poxviridae comprises several viruses that are capable of infecting a wide range of hosts. One of the most widespread OPXVs is the Vaccinia virus (VACV), which circulates in zoonotic cycles in South America, especially in Brazil, infecting domestic and wild animals and humans and causing economic losses as well as impacting public health. Despite this, little is known about the presence and/or exposure of neotropical primates to orthopoxviruses in the country. In this study, we report the results of a search for evidence of OPVX infections in neotropical free-living primates in the state of Minas Gerais, southeast Brazil. The sera or liver tissues of 63 neotropical primates were examined through plaque reduction neutralization tests (PRNT) and real-time PCR. OPXV-specific neutralizing antibodies were detected in two sera (4.5%) from Callithrix penicillata, showing 55% and 85% reduction in plaque counts, evidencing their previous exposure to the virus. Both individuals were collected in urban areas. All real-time PCR assays were negative. This is the first time that evidence of OPXV exposure has been detected in C. penicillata, a species that usually lives at the interface between cities and forests, increasing risks of zoonotic transmissions through spillover/spillback events. In this way, studies on the circulation of OPXV in neotropical free-living primates are necessary, especially now, with the monkeypox virus being detected in new regions of the planet.

High overlap of zoonotic helminths between wild mammalian predators and rural dogs - an emerging One Health concern?

The concept of One Health emphasizes the interdependence of human, animal and environmental health and is of growing significance, in part owing to the problems related to emerging infectious diseases of wildlife origin. Wild mammalian predators are a potential risk factor for transmission of zoonotic pathogens to domesticated animals and humans. This is especially relevant in rural areas, where transmission of zoonotic pathogens can occur particularly efficiently when free-ranging dogs are present. The main aim of this study was to determine helminth infections among wild mammalian predators and evaluate the overlap between helminth faunas of wild mammals and dogs. Scat samples of predators were collected in coastal areas of Western Estonia and genetic methodology applied for the correct identification of predator species from their scat. Parasitic helminths of mammalian predators in the scat samples were analysed and compared with dog data from a previous study. High helminth prevalence (~90%) was found in dominant predator species in the area, namely the red fox (Vulpes vulpes) and golden jackal (Canis aureus). Moreover, the helminth fauna of both wild species, including potentially zoonotic helminths, overlapped largely with that of rural dogs in the same area. The results, together with the ones from earlier parasitological studies among humans in Estonia, emphasize the potential risk of pathogen transmission from wild mammalian predators to dogs and from dogs to humans, making parasitic diseases of wildlife a One Health concern.

Toxoplasmosis in Human and Animals Around the World. Diagnosis and Perspectives in the One Health Approach

Toxoplasmosis is a unique health disease that significantly affects the health of humans, domestic animals, wildlife and is present in ecosystems, including water, soil and food. Toxoplasma gondii is one of the best-adapted parasites in the word. This parasite is able to persist for long periods in its hosts, in different geographic regions of the word. This review summarizes the current literature of these themes, focusing on: (1) toxoplasmosis, a zoonotic infection; (2) One health approach and toxoplasmosis; (3) human toxoplasmosis; (4) animal toxoplasmosis; (5) toxoplasmosis diagnosis, as immunological, parasitological and molecular diagnosis; (6) T. gondii outbreaks caused by infected meat, milk and dairy products, as well as, vegetables and water consume; (7) studies in experimental models; (8) genetic characterization of T. gondii strains; (9) extracellular vesicles and miRNA; and (10) future perspectives on T. gondii and toxoplasmosis. The vast prevalence of toxoplasmosis in both humans and animals and the dispersion and resistence of T. gondii parasites in environment highlight the importance of the one health approach in diagnostic and control of the disease. Here the different aspects of the one health approach are presented and discussed.

Explosive networking: The role of adaptive host radiations and ecological opportunity in a species-rich host-parasite assembly

Many species-rich ecological communities emerge from adaptive radiation events. Yet the effects of adaptive radiation on community assembly remain poorly understood. Here, we explore the well-documented radiations of African cichlid fishes and their interactions with the flatworm gill parasites Cichlidogyrus spp., including 10,529 reported infections and 477 different host-parasite combinations collected through a survey of peer-reviewed literature. We assess how evolutionary, ecological, and morphological parameters determine host-parasite meta-communities affected by adaptive radiation events through network metrics, host repertoire measures, and network link prediction. The hosts' evolutionary history mostly determined host repertoires of the parasites. Ecological and evolutionary parameters predicted host-parasite interactions. Generally, ecological opportunity and fitting have shaped cichlid-Cichlidogyrus meta-communities suggesting an invasive potential for hosts used in aquaculture. Meta-communities affected by adaptive radiations are increasingly specialised with higher environmental stability. These trends should be verified across other systems to infer generalities in the evolution of species-rich host-parasite networks.

Negative seroprevalence for Toxoplasma gondii in free-living primates from Central Amazonia

This study presents 35 negative serologies for antibodies anti-T. gondii in free-living primates from Central Amazonia. Our results suggest that these populations have not had contact with the parasite and, therefore, do not have antibodies. This was the first study surveying T. gondii in Cacajao, Callicebus, Pithecia, and Saguinus monkeys.

Wild carnivores and Thelazia callipaeda zoonotic eyeworms: A focus on wolves

Thelazia callipaeda is a zoonotic parasite causing ocular disease in domestic dogs, cats, several wild carnivores, hares, and humans. This nematode is widely distributed in Europe, where it is transmitted by the drosophilid fly Phortica variegata. Since the first report of infection in grey wolves (Canis lupus) from southern Italy, other cases of thelaziosis have been recorded in this animal species throughout Europe, raising questions about their role in spreading T. callipaeda. Indeed, for their wandering behavior through long distances and living in woody areas where the vectors thrive, wolves may act as reservoirs and spreaders of thelaziosis. In this study we reviewed the literature about wolves acting as reservoirs of T. callipaeda in Europe. In addition, we report the first detection of T. callipaeda eyeworms in grey wolves in the Italian Alps, discussing its possible implications in the epidemiology of thelaziosis in the Alpine landscape. Animals (n = 3) included in this study were originated from the Italian Alps, one juvenile male wolf was found dead, and the other two were seven-year-old males translocated from Piedmont region to a Zoological Garden, in Tuscany. All animals were infected with eyeworms, which were morphologically and molecularly identified as T. callipaeda. Data herein presented confirm those available in the literature about the circulation of a unique cox1 haplotype in Europe. In addition, the report of T. callipaeda in wolves from the Alps suggests an ecological continuity of habitats which are suitable for the distribution of T. callipaeda from the southern to northern Italy through the Apennine backbone. Retrospectively, it could also explain the spreading of the oriental eyeworm infection in Europe over the last 20 years with many wild carnivores, such as foxes and possibly wolves, playing a pivotal role as reservoirs of the infection for dogs, cats and humans.

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Wolves may play important role in the transmission cycle of Thelazia callipaeda.

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There is a need of passive-surveillance programs of this zoonotic nematode in wild carnivores.

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This is the first report of Thelazia callipaeda in wolves from the Italian Alps.

Identification of Oocyst-Driven Toxoplasma gondii Infections in Humans and Animals through Stage-Specific Serology-Current Status and Future Perspectives

The apicomplexan zoonotic parasite Toxoplasma gondii has three infective stages: sporozoites in sporulated oocysts, which are shed in unsporulated form into the environment by infected felids; tissue cysts containing bradyzoites, and fast replicating tachyzoites that are responsible for acute toxoplasmosis. The contribution of oocysts to infections in both humans and animals is understudied despite being highly relevant. Only a few diagnostic antigens have been described to be capable of discriminating which parasite stage has caused an infection. Here we provide an extensive overview of the antigens and serological assays used to detect oocyst-driven infections in humans and animals according to the literature. In addition, we critically discuss the possibility to exploit the increasing knowledge of the T. gondii genome and the various 'omics datasets available, by applying predictive algorithms, for the identification of new oocyst-specific proteins for diagnostic purposes. Finally, we propose a workflow for how such antigens and assays based on them should be evaluated to ensure reproducible and robust results.

Vector-borne zoonotic blood parasites in wildlife from Ecuador: A report and systematic review

Background and Aim:

Ecuador is a hugely diverse country, but information on infectious diseases in local wild animals is scarce. The aim of this study was to screen the presence of blood parasites in free-ranging wild animals admitted to the Wildlife Hospital at Universidad San Francisco de Quito, from April 2012 to January 2019.

Materials and Methods:

We identified blood parasites by microscopic observation of blood smears from free-ranging wildlife species that attended the Wildlife Hospital of Universidad San Francisco de Quito (Ecuador) from April 2012 to January 2019.

Results:

The microscopic evaluations of animals as potential reservoirs for vector-borne zoonotic blood parasites revealed the presence of Anaplasma spp., Babesia spp., Ehrlichia spp., Hepatozoon spp., microfilaria, Mycoplasma spp., and Trypanosoma spp. in previously unreported wildlife species. In addition, we performed a systematic review to understand the current knowledge gaps in the context of these findings.

Conclusion:

Our data contribute to the knowledge of blood parasites in wildlife from Ecuador. Furthermore, the potential transmission of these parasites to humans and domestic animals, current anthropogenic environmental changes in the region, and the lack of information on this suggest the importance of our results and warrant further investigations on infectious diseases in animals and humans and their relationship with environmental health as key domains of the One Health concept.

Implications of Zoonoses From Hunting and Use of Wildlife in North American Arctic and Boreal Biomes: Pandemic Potential, Monitoring, and Mitigation

The COVID-19 pandemic has re-focused attention on mechanisms that lead to zoonotic disease spillover and spread. Commercial wildlife trade, and associated markets, are recognized mechanisms for zoonotic disease emergence, resulting in a growing global conversation around reducing human disease risks from spillover associated with hunting, trade, and consumption of wild animals. These discussions are especially relevant to people who rely on harvesting wildlife to meet nutritional, and cultural needs, including those in Arctic and boreal regions. Global policies around wildlife use and trade can impact food sovereignty and security, especially of Indigenous Peoples. We reviewed known zoonotic pathogens and current risks of transmission from wildlife (including fish) to humans in North American Arctic and boreal biomes, and evaluated the epidemic and pandemic potential of these zoonoses. We discuss future concerns, and consider monitoring and mitigation measures in these changing socio-ecological systems. While multiple zoonotic pathogens circulate in these systems, risks to humans are mostly limited to individual illness or local community outbreaks. These regions are relatively remote, subject to very cold temperatures, have relatively low wildlife, domestic animal, and pathogen diversity, and in many cases low density, including of humans. Hence, favorable conditions for emergence of novel diseases or major amplification of a spillover event are currently not present. The greatest risk to northern communities from pathogens of pandemic potential is via introduction with humans visiting from other areas. However, Arctic and boreal ecosystems are undergoing rapid changes through climate warming, habitat encroachment, and development; all of which can change host and pathogen relationships, thereby affecting the probability of the emergence of new (and re-emergence of old) zoonoses. Indigenous leadership and engagement in disease monitoring, prevention and response, is vital from the outset, and would increase the success of such efforts, as well as ensure the protection of Indigenous rights as outlined in the United Nations Declaration on the Rights of Indigenous Peoples. Partnering with northern communities and including Indigenous Knowledge Systems would improve the timeliness, and likelihood, of detecting emerging zoonotic risks, and contextualize risk assessments to the unique human-wildlife relationships present in northern biomes.

Inuit Country Food and Health during Pregnancy and Early Childhood in the Circumpolar North: A Scoping Review

Inuit communities in the Circumpolar North have experienced a nutrition transition characterized by the decreased intake of culturally important, nutrient-rich traditional food (country food), and an increased intake of market food, resulting in concerns over reduced diet quality and emerging chronic diseases. Nutrition in early life is critical for development, may influence health risks in later life, and is an important concern for Inuit community health. The goal of this scoping review was to characterize the nature, extent, and range of the published literature on Inuit country food and health in pregnancy and childhood. A search string was developed and applied to three databases, followed by title and abstract screening and full text review. Articles published between 1995 and 2019 were included, and data were extracted and summarized descriptively. The number of articles generally increased over time, despite the unequal geographic distribution of articles. The majority of the articles focused on environmental contaminants, and one-quarter described nutrient adequacy. Few articles described food security or food safety in pregnancy, and the most utilized quantitative methods. Gaps in understanding of country food use in pregnancy and early childhood highlight areas of future research to support public health policy for this population. Given the critical role of good nutrition in early life and the important contribution country food makes to diet quality for Inuit, further understanding of this interface is warranted.

Corals as canaries in the coalmine: Towards the incorporation of marine ecosystems into the 'One Health' concept

'One World - One Health' is a developing concept which aims to explicitly incorporate linkages between the environment and human society into wildlife and human health care. Past work in the field has concentrated on aspects of disease, particularly emerging zoonoses, and focused on terrestrial systems. Here, we argue that marine environments are crucial components of the 'One World - One Health' framework, and that coral reefs are the epitome of its underlying philosophy. That is, they provide vast contributions to a wide range of ecosystem services with strong and direct links to human well-being. Further, the sensitivity of corals to climate change, and the current emergence of a wide range of diseases, make coral reefs ideal study systems to assess links, impacts, and feedback mechanisms that can affect human and ecosystem health. There are well established protocols for monitoring corals, as well as global networks of coral researchers, but there remain substantial challenges to understanding these complex systems, their health and links to provisioning of ecosystem services. We explore these challenges and conclude with a look at how developing technology offers potential ways of addressing them. We argue that a greater integration of coral reef research into the 'One World - One Health' framework will enrich our understanding of the many links within, and between, ecosystems and human society. This will ultimately support the development of measures for improving the health of both humans and the environment.

A global assessment of Echinococcus multilocularis infections in domestic dogs: proposing a framework to overcome past methodological heterogeneity

Echinococcus multilocularis, the aetiological agent of human Alveolar Echinococcosis, is transmitted between small mammals and wild or domestic canids. Dogs infected with E. multilocularis as dead-end hosts. Whereas E. multilocularis infections in wild hosts and humans have been well-studied in recent decades, infections in domestic dogs are sparsely reported. This literature review and meta-analysis highlighted gaps in the available data and provided a re-assessment of the global distribution of domestic dog E. multilocularis infections. We found 46 published articles documenting the prevalence of E. multilocularis in domestic dogs from 21 countries across Europe, Asia and North America. Apparent prevalence estimates ranged from 0.00% (0.00-0.33%) in Germany to 55.50% (26.67-81.12%) in China. Most studies were conducted in areas of high human Alveolar Echinococcosis. By accounting for reassessed diagnostic sensitivity and specificity, we estimated true prevalence in a subset of studies, which varied between 0.00% (0.00-12.42%) and 41.09% (21.12-65.81%), as these true prevalence estimates were seldom reported in the articles themselves. Articles also showed a heavy emphasis on rural dogs, dismissing urban ones, which is concerning due to the role urbanisation plays in the transmission of zoonotic diseases, especially those utilising pets as definitive hosts. Lastly, population studies on canine Alveolar Echinococcosis were absent, highlighting the relative focus on human rather than animal health. We thus developed a framework for investigating domestic dog E. multilocularis infections and performing risk assessment of dog-associated transmission to fill the gaps found in the literature.

Invertebrate health in marine protected areas (MPAs)

Marine protected areas (MPAs) consist of various categories of safeguarded areas in the marine environment, from semi-protected areas to total no take zones. The reported effects of MPAs are overwhelmingly positive, with numerous reports of fish size (biomass), abundance (recovery) and diversity increases, however, literature is lacking on the role and consequences of MPAs on parasite and disease dynamics, and in particular, invertebrate health. The implementation of MPAs has been known to alter trophic cascades and community dynamics, and with invertebrates commonly at the base of these systems, it is vital that their status is investigated. Overcrowding in areas closed to fishing is known to have parasitological consequences in some scenarios, and land/water use change has been known to alter host and vector communities, possibly elevating disease risk. Equally, reserves can be used as tools for alleviating impacts of marine disease. This review aims to consolidate extant literature and provide a comprehensive viewpoint on how invertebrates (and their health status) can be affected by MPAs, which are increasingly being implemented based on the relative urgency now being placed on protecting global biodiversity. In highlighting the paucity of knowledge surrounding MPAs and disease, especially that of the unenigmatic invertebrate groups, this review, published in the Special Issue on 'Invertebrates as One Health Sentinels', provides an opportunity for wide dissemination and provocation of further research in this area.

Food Safety Considerations Related to the Consumption and Handling of Game Meat in North America

Emerging foodborne pathogens present a threat to public health. It is now recognized that several foodborne pathogens originate from wildlife as demonstrated by recent global disease outbreaks. Zoonotic spillover events are closely related to the ubiquity of parasitic, bacterial, and viral pathogens present within human and animal populations and their surrounding environment. Foodborne diseases have economic and international trade impacts, incentivizing effective wildlife disease management. In North America, there are no food safety standards for handling and consumption of free-ranging game meat. Game meat consumption continues to rise in North America; however, this growing practice could place recreational hunters and game meat consumers at increased risk of foodborne diseases. Recreational hunters should follow effective game meat food hygiene practices from harvest to storage and consumption. Here, we provide a synthesis review that evaluates the ecological and epidemiological drivers of foodborne disease risk in North American hunter populations that are associated with the harvest and consumption of terrestrial mammal game meat. We anticipate this work could serve as a foundation of preventive measures that mitigate foodborne disease transmission between free-ranging mammalian and human populations.

Ecology eclipses phylogeny as a major driver of nematode parasite community structure in a graminivorous primate

Understanding the relative strength of ecology and phylogeny in shaping parasite communities can inform parasite control and wildlife conservation initiatives while contributing to the study of host species evolution.We tested the relative strengths of phylogeny and ecology in driving parasite community structure in a host whose ecology diverges significantly from that of its closest phylogenetic relatives.We characterized the gastrointestinal (GI) parasite community of wild geladas (Theropithecus gelada), primates that are closely related to baboons but specialized to graminovory in the Ethiopian Highlands.Geladas exhibited very constrained GI parasite communities: only two genera (Oesophagostomum and Trichostrongylus) were identified across 303 samples. This is far below the diversity reported for baboons (Papio spp.) and at the low end of the range of domestic grazers (e.g., Bos taurus, Ovis aries) inhabiting the same region and ecological niche.Using deep amplicon sequencing, we identified 15 amplicon sequence variants (ASVs) within the two genera, seven of which matched to Oesophagostomum sp., seven to Trichostrongylus sp., and one to T. vitrinus.Population was an important predictor of ASV richness. Geladas in the most ecologically disturbed area of the national park exhibited ~4x higher ASV richness than geladas at a less disturbed location within the park.In this system, ecology was a stronger predictor of parasite community structure than phylogeny, with geladas sharing more elements of their parasite communities with other grazers in the same area than with closely related sister taxa.

Norway rat (Rattus norvegicus) ectoparasites in livestock production systems from central Argentina: Influencing factors on parasitism

Haematophagous ectoparasites are worldwide vectors of many zoonotic bacterial diseases, both emerging and re-emerging, whose incidences are rising. Livestock development alters different environmental characteristics such as the microclimate of a site, changing the availability, density and susceptibility of the hosts to pathogens and vectors, indirectly influencing the spread and persistence of a disease within an ecosystem. The Norway rat (Rattus norvegicus), the most abundant vertebrate pest species found on livestock farms from Argentina, is a reservoir for several important zoonotic bacteria and may harbor ectoparasite species, which act as their vectors. Even though the Norway rat is widely known for its role as an ectoparasite host, the ecological characteristics of their ectoparasite communities and the related factors with parasitism on livestock farms have never been described. In the present study, we describe the ectoparasite community in Norway rats from central Argentina livestock farms, while also depicting the influencing factors on both ectoparasite occurrence and abundance. Ectoparasites were collected from rats captured in 20 sites from Buenos Aires province, between the winter of 2016 and the summer of 2018. A total of 1441 ectoparasite individuals were collected from 159 Norway rat individuals [Total ectoparasite prevalence = 69.2%; Mean ectoparasite specimen abundance (± CI) = 9.06 ± 2.32 ectoparasite individuals per rat; Mean ectoparasite specimen intensity (±CI) = 13.10 ± 3.08 ectoparasite individuals per infested rat found]. Ectoparasite assemblage consisted of four cosmopolitan species, recognized for their sanitary relevance: mites (Laelapidae: Laelaps nuttalli and Laelaps echidninus), lice (Polyplacidae: Polyplax spinulosa) and fleas (Pulicidae: Xenopsylla cheopis). We observed higher Norway rat abundance in sites related to higher ectoparasite occurrence and abundance frequencies on the rats. Additionally, ectoparasites were more abundant on rats in warm seasons and on male individuals, over female rats. Moreover, the geographical location of the studied sites influenced the ectoparasite assemblage structure observed on the rats. This study broadens the knowledge on the role of Norway rats as zoonotic ectoparasites hosts and analyzes the drivers influencing ectoparasite occurrence and abundance on the most populated region of Argentina, which is also the region with the most intensive livestock farming. Therefore, this survey may assist in evaluating potential risks for humans and generate effective sanitary control strategies for ectoparasite-borne infectious diseases.

EcoHealth and One Health: A theory-focused review in response to calls for convergence

BACKGROUND

EcoHealth and One Health are two major approaches broadly aimed at understanding the links between human, animal, and environment health. There have been increasing calls for convergence between the two. If convergence is desired, greater clarity regarding the underlying theoretical assumptions of both approaches is required. This would also support integrated research to effectively address complex health issues at the human, animal and environment interface. To better understand the areas of overlap and alignment, we systematically compared and contrasted the theoretical assumptions of both approaches.

OBJECTIVES

We aimed to gain a more in-depth understanding of the ontological, epistemological and methodological underpinnings of EcoHealth and One Health in order to identify areas of difference and overlap, and consider the extent to which closer convergence between the two may be possible.

METHODS

We undertook a scoping review of literature about the ontological, epistemological and methodological positions of EcoHealth and One Health, and analyzed these according to Lincoln, Lynham and Guba's paradigm framework.

RESULTS

EcoHealth and One Health are both collaborative, systems-focused approaches at the human, animal, and ecosystem health interface. EcoHealth typically leans towards constructivist-leaning assumptions. Many consider this a necessary aspiration for One Health. However, in practice One Health remains dominated by the veterinary and medical disciplines that emphasize positivist-leaning assumptions.

DISCUSSION

The aspirations of EcoHealth and One Health appear to overlap at the conceptual level, and may well warrant closer convergence. However, further shared discussions about their epistemological and ontological assumptions are needed to reconcile important theoretical differences, and to better guide scopes of practice. Critical realism may be a crucial theoretical meeting point. Systems thinking methods (with critical realist underpinnings), such as system dynamics modelling, are potentially useful methodologies for supporting convergent practice.

Multi-pathogen serological survey of migratory caribou herds: A snapshot in time

Pathogens can impact host survival, fecundity, and population dynamics even when no obvious disease is observed. Few baseline data on pathogen prevalence and diversity of caribou are available, which hampers our ability to track changes over time and evaluate impacts on caribou health. Archived blood samples collected from ten migratory caribou herds in Canada and two in Greenland were used to test for exposure to pathogens that have the potential to effect population productivity, are zoonotic or are emerging. Relationships between seroprevalence and individual, population, and other health parameters were also examined. For adult caribou, the highest overall seroprevalence was for alphaherpesvirus (49%, n = 722), pestivirus (49%, n = 572) and Neospora caninum (27%, n = 452). Lower seroprevalence was found for parainfluenza virus type 3 (9%, n = 708), Brucella suis (2%, n = 758), and Toxoplasma gondii (2%, n = 706). No animal tested positive for antibodies against West Nile virus (n = 418) or bovine respiratory syncytial virus (n = 417). This extensive multi-pathogen survey of migratory caribou herds provides evidence that caribou are exposed to pathogens that may have impacts on herd health and revealed potential interactions between pathogens as well as geographical differences in pathogen exposure that could be linked to the bio-geographical history of caribou. Caribou are a keystone species and the socio-economic cornerstone of many indigenous cultures across the North. The results from this study highlight the urgent need for a better understanding of pathogen diversity and the impact of pathogens on caribou health.

The One Health Approach to Toxoplasmosis: Epidemiology, Control, and Prevention Strategies

One Health is a collaborative, interdisciplinary effort that seeks optimal health for people, animals, plants, and the environment. Toxoplasmosis, caused by Toxoplasma gondii, is an intracellular protozoan infection distributed worldwide, with a heteroxenous life cycle that practically affects all homeotherms and in which felines act as definitive reservoirs. Herein, we review the natural history of T. gondii, its transmission and impacts in humans, domestic animals, wildlife both terrestrial and aquatic, and ecosystems. The epidemiology, prevention, and control strategies are reviewed, with the objective of facilitating awareness of this disease and promoting transdisciplinary collaborations, integrative research, and capacity building among universities, government agencies, NGOs, policy makers, practicing physicians, veterinarians, and the general public.

Serological and Molecular Investigation on Toxoplasma gondii Infection in Wild Birds

Toxoplasma gondii is an obligate apicomplexan zoonotic parasite that infects humans and other animals and is responsible for toxoplasmosis. This parasite causes one of the most common parasitic infections in humans worldwide. Toxoplasmosis meets the requirements for a One Health Disease due to its ability to affect the health of human beings as well as domestic and free ranging animals. Integrating human, domestic animal, and wildlife data could better assess the risk and devise methods of control. A first step of such an approach would be the knowledge of the prevalence of parasitosis in humans and animals in selected areas. Therefore, the aim of the present study was to evaluate the occurrence of Toxoplasma infection in 216 free ranging birds belonging to different genera/species by serology and molecular techniques. Twenty-five out of 216 animals (11.6%) were positive to the immunofluorescence antibody test (IFAT) with antibody titers ranging from 1/20 to 1/320, and 19 of them (8.8%) also showed a positive PCR for Toxoplasma DNA. The results confirmed the widespread occurrence of Toxoplasma infection in wild birds and serological data were corroborated by molecular results in birds that also had low antibody titers. The knowledge of the wide occurrence of the parasite in game and wild birds should enhance the accurate estimation of the risks in handling, managing, and eating these species with regard to domestic carnivores as well as the impact of viscera and offal in the environment.

Dogs (Canis familiaris) as Sentinels for Human Infectious Disease and Application to Canadian Populations: A Systematic Review

In a world where climate change, vector expansion, human activity, and pathogen dispersal do not respect boundaries, the human⁻animal⁻pathogen interface has become less defined. Consequently, a One Health approach to disease surveillance and control has generated much interest across several disciplines. This systematic review evaluates current global research on the use of domestic dogs as sentinels for human infectious disease, and critically appraises how this may be applied within Canada. Results highlighted a bias in research from high- and middle-income-economy countries, with 35% of the studies describing data from the Latin America/Caribbean region, 25% from North America, and 11% from the European/Central Asia region. Bacteria were the most studied type of infectious agent, followed by protozoa, viruses, helminths, and fungi. Only six out of 142 studies described disease in Canada: four researched a variety of pathogens within Indigenous communities, one researched Borrelia burgdorferi in British Columbia, and one researched arboviruses in Quebec. Results from this review suggest that dogs could provide excellent sentinels for certain infectious-disease pathogens in Canada, yet are currently overlooked. Further research into the use of dog-sentinel surveillance is specifically recommended for California serogroup viruses, Chikungunya virus, West Nile virus, Lyme borreliosis, Rickettsia spp., Ehrlichia spp., and Dirofilaria immitis.

A review of wildlife tourism and meta-analysis of parasitism in Africa's national parks and game reserves

The recent increase of parasitic diseases associated with wildlife tourism can be traced to human contact with wildlife and intense modification of wildlife habitat. The continental estimates of parasitic diseases among visited wildlife-tourists and mammalian wildlife present in conservation areas are lacking; therefore, a general review was necessary to provide insights into Africa's parasitic disease burden and transmission between humans and wildlife. A two-step analysis was conducted with searches in Ovid MEDLINE, EMBASE, PubMed, Web of Science and Global Health. All diseases reported without prevalence were grouped and analysed as categorical data while meta-analysis of prevalence rates of parasitic diseases in wildlife from national parks and reserves in Africa was conducted. Only 4.7% of the tourist centres reported routine wildlife diagnosis for parasitic diseases. Disease intensity shows that cryptosporidiosis and seven other parasitic diseases were observed in both human and wildlife; however, no significant difference in intensity between human and wildlife hosts was observed. Schistosomiasis intensity reports showed a significant increase (P < 0.05) while entamoebiasis showed a significant decrease (P < 0.05) in humans as compared to wildlife. Visiting tourists were more infected with malaria, while wildlife was more infected with parasitic gastroenteritis (PGE). The meta-analysis of wildlife revealed the highest prevalence of PGE with mixed parasites and lowest prevalence of Giardia spp. at 99.9 and 5.7%, respectively. The zoonotic and socioeconomic impact of some of these parasites could pose a severe public threat to tourism. Pre- and post-travel clinical examinations are important for tourists while routine examination, treatment and rational surveillance are important for these animals to improve wildlife tourism.

Neglected Tropical Disease Control - The Case for Adaptive, Location-specific Solutions

The world is experiencing environmental and social change at an unprecedented rate, with the effects being felt at local, regional, and international scales. This phenomenon may disrupt interventions against neglected tropical diseases (NTDs) that operate on the basis of linear scaling and 'one-size-fits-all'. Here we argue that investment in field-based data collection and building modelling capacity is required; that it is important to consider unintended consequences of interventions; that inferences can be drawn from wildlife ecology; and that interventions should become more location-specific. Collectively, these ideas underpin the development of adaptive decision-support tools that are sufficiently flexible to address emerging issues within the Anthropocene.

The echinococcoses in Asia: The present situation

Human alveolar and cystic echinococcosis, caused by the accidental ingestion of eggs of the tapeworms Echinococcus multilocularis and Echinococcus granulosus sensu lato, respectively, are endemic in Asia. Various Echinococcus species are maintained in domesticated and/or wild mammals through predator-prey interactions. Molecular analysis is used to help differentiate infecting parasite species and genotypes, with the goal of better understanding parasite life cycles in order to aid in the planning and implementation of control programs. This paper discusses the various echinococcoses in Asia, with limited reference to neighboring areas, including parts of Central Asia, Russia, Europe and North America.

Using experimental de-worming to measure the immunological and pathological impacts of lungworm infection in cane toads

The immunological and pathological consequences of parasite infection can be more rigorously assessed from experimental manipulation than from correlational studies of natural infections. We used anthelmintic treatment to experimentally decrease intensities of lungworm infection in captive and free-ranging wild cane toads to assess parasite impacts on host immune responses. First, we administered the anthelmintic drug Ivermectin to both infected and uninfected toads, to distinguish drug effects per se from the impacts of killing lungworms. Worms began dying and decomposing <48 h after injection. The only immunological variables that were affected by anthelmintic treatment were bactericidal capacity of the blood which increased in parasitized toads (presumably triggered by decomposing worms in the lungs), and the phagocytic capacity of blood (which increased in both infected and uninfected toads); the latter effect presumably was caused by the injection of Ivermectin per se rather than removal of parasites. Second, we looked at correlates of variation in the infection intensity induced by de-worming (in both captive and free-ranging toads) over an eight-week period. Heavier lungworm infection was associated with increased phagocytic ability of the host's blood, and a reduction in the host's liver mass (and hence, energy stores). Experimental de-worming thus revealed pathological and immunological costs of the presence of lungworms, and of their removal by anthelmintic injection.

Arthropod-borne agents in wild Orinoco geese (Neochen jubata) in Brazil

Although Orinoco goose (Neochen jubata) is an anatid species widely distributed in South America, scarce are the reports on the occurrence of arthropod-borne pathogens in this avian species. The present work aimed to verify, by serological and molecular methods, the occurrence of haemosporida piroplasmids and Anaplasmataceae agents in wild Orinoco geese captured in Brazil. Between 2010 and 2014, 62 blood samples were collected from free-living geese captured in the Araguaia River, Goiás State, Brazil. Six geese (10%) were seropositive for Anaplasma phagocytophilum, showing titers ranging from 40 and 80. Twenty out of 62 blood samples (32.25%) were positive in nested PCR for hemosporidia (cytochrome b gene). Fifteen and five sequences shared identity with Haemoproteus and Plasmodium, respectively. Six out of 62 blood samples (9.68%) were positive in nested PCR for Babesia spp. (18S rRNA gene); one sequence showed to be closely related to Babesia vogeli. Thirty (48.38%) out of 62 Orinoco geese blood samples were positive in nested cPCR assays for Anaplasmataceae agents (16S rRNA gene): three for Anaplasma spp. and 27 for Ehrlichia. Six geese were simultaneously positive to Haemoproteus and Ehrlichia; three animals were co-positive to different Ehrlichia species/genotypes; and one goose sample was positive for both Anaplasma and Ehrlichia. The present work showed the occurrence of Ehrlichia, Anaplasma, Babesia, Plasmodium, and Haemoproteus species in free-living N. jubata in Brazil. The threat of these arthropod-borne pathogens in Orinoco goose's fitness, especially during the breading season, should be assessed in the future.

A Comparison of Three Holistic Approaches to Health: One Health, EcoHealth, and Planetary Health

Several holistic and interdisciplinary approaches exist to safeguard health. Three of the most influential concepts at the moment, One Health, EcoHealth, and Planetary Health, are analyzed in this paper, revealing similarities and differences at the theoretical conceptual level. These approaches may appear synonymous, as they all promote the underlying assumption of humans and other animals sharing the same planet and the same environmental challenges, infections and infectious agents as well as other aspects of physical—and possibly mental—health. However, we would like to illuminate the differences between these three concepts or approaches, and how the choice of terms may, deliberately or involuntary, signal the focus, and underlying values of the approaches. In this paper, we have chosen some proposed and well-known suggestions of definitions. In our theoretical analysis, we will focus on at least two areas. These are (1) the value of the potential scientific areas which could be included and (2) core values present within the approach. In the first area, our main concern is whether the approaches are interdisciplinary and whether the core scientific areas are assigned equal importance. For the second area, which is rather wide, we analyze core values such as biodiversity, health, and how one values humans, animals, and ecosystems. One Health has been described as either a narrow approach combining public health and veterinary medicine or as a wide approach as in the wide-spread “umbrella” depiction including both scientific fields, core concepts, and interdisciplinary research areas. In both cases, however, safeguarding the health of vertebrates is usually in focus although ecosystems are also included in the model. The EcoHealth approach seems to have more of a biodiversity focus, with an emphasis on all living creatures, implying that parasites, unicellular organisms, and possibly also viruses have a value and should be protected. Planetary Health, on the other hand, has been put forward as a fruitful approach to deal with growing threats in the health area, not least globally. We conclude that there are actually important differences between these three approaches, which should be kept in mind when using any of these terms.

Precision wildlife medicine: applications of the human-centred precision medicine revolution to species conservation

The current species extinction crisis is being exacerbated by an increased rate of emergence of epizootic disease. Human-induced factors including habitat degradation, loss of biodiversity and wildlife population reductions resulting in reduced genetic variation are accelerating disease emergence. Novel, efficient and effective approaches are required to combat these epizootic events. Here, we present the case for the application of human precision medicine approaches to wildlife medicine in order to enhance species conservation efforts. We consider how the precision medicine revolution, coupled with the advances made in genomics, may provide a powerful and feasible approach to identifying and treating wildlife diseases in a targeted, effective and streamlined manner. A number of case studies of threatened species are presented which demonstrate the applicability of precision medicine to wildlife conservation, including sea turtles, amphibians and Tasmanian devils. These examples show how species conservation could be improved by using precision medicine techniques to determine novel treatments and management strategies for the specific medical conditions hampering efforts to restore population levels. Additionally, a precision medicine approach to wildlife health has in turn the potential to provide deeper insights into human health and the possibility of stemming and alleviating the impacts of zoonotic diseases. The integration of the currently emerging Precision Medicine Initiative with the concepts of EcoHealth (aiming for sustainable health of people, animals and ecosystems through transdisciplinary action research) and One Health (recognizing the intimate connection of humans, animal and ecosystem health and addressing a wide range of risks at the animal-human-ecosystem interface through a coordinated, collaborative, interdisciplinary approach) has great potential to deliver a deeper and broader interdisciplinary-based understanding of both wildlife and human diseases.

ANIMAL WELFARE FROM MOUSE TO MOOSE--IMPLEMENTING THE PRINCIPLES OF THE 3RS IN WILDLIFE RESEARCH

The concept of the 3Rs (replacement, reduction, and refinement) was originally developed for improving laboratory animal welfare and is well known in biomedical and toxicologic research. The 3Rs have so far gained little attention in wildlife research, and there could be several reasons for this. First, researchers may prioritize the welfare of populations and ecosystems over the welfare of individual animals. The effects of research on individual animals can, however, impact welfare and research quality at group and population levels. Second, researchers may find it difficult to apply the 3Rs to studies of free-living wildlife because of the differences between laboratory and wild animals, species, research environment, and purpose and design of the studies. There are, however, several areas where it is possible to transfer the 3R principles to wildlife research, including replacement with noninvasive research techniques, reduction with optimized experimental design, and refinement with better methods of capture, anesthesia, and handling. Third, researchers may not have been trained in applying the 3Rs in wildlife research. This training is needed since ethics committees, employers, journal publishers, and funding agencies increasingly require researchers to consider the welfare implications of their research. In this paper, we compare the principles of the 3Rs in various research areas to better understand the possibilities and challenges of the 3Rs in wildlife research. We emphasize the importance of applying the 3Rs systematically throughout the research process. Based on experiences from laboratory research, we suggest three key factors to enhance implementation of the 3Rs in wildlife research: 1) organizational structure and management, 2) 3R awareness, and 3) research innovation, validation, and implementation. Finally, we encourage an interdisciplinary approach to incorporate the 3R principles in wildlife research. For improved animal welfare and increased research quality, researchers have moral obligations to include the 3Rs into all research areas, including wildlife research.

Enhancement of wildlife disease surveillance using multiplex quantitative PCR: development of qPCR assays for major pathogens in UK squirrel populations

Rapid development in polymerase chain reaction (PCR) technology has revolutionised the speed and accuracy of many diagnostic assays. However, comparatively few wildlife epidemiological studies use quantitative PCR (qPCR) for pathogen detection, even fewer employ an internal control, to ensure confidence in negative results, and PCR's ability to multiplex and therefore detect several targets in a single reaction is underutilised. Here, we describe the development of two multiplex qPCR assays for the red and grey squirrel that detect the pathogens squirrelpox virus (SQPV) and adenovirus in squirrels (SADV), both of which cause mortality in the red squirrel. Both assays use a section of the squirrel phosphoglycerate kinase gene as an endogenous internal control that identifies and compensates for both, inadequate sampling or PCR inhibition. Tests on infected squirrel tissue demonstrate that simple swab samples (particularly from distal antebrachial skin) are sufficient to detect and identify the relative quantity of SQPV DNA in both squirrel species, while rectal swabs and blood cell pellets can be used to reliably indicate SADV infection. These assays are sensitive and specific with an endogenous internal control providing confidence in negative results and allowing comparison across laboratories. Using such assays should prove advantageous in wildlife studies with limited resources while allowing the maximum data yield.

One Health: competing perspectives in an emerging field

Over the last decade, One Health has attracted considerable attention from researchers and policymakers. The concept argues that the fields of human, animal and environmental health ought to be more closely integrated. Amid a flurry of conferences, projects and publications, there has been substantial debate over what exactly One Health is and should be. This review summarizes the main trends in this emerging discussion, highlighting the fault lines between different perspectives on One Health. Some have shown that One Health's call to synthesize knowledge from different disciplines can lead to better interventions. Others, however, argue that One Health's challenge to existing practice must go further, and set out a vision that foregrounds the social and economic drivers of disease. Meanwhile, recent examples of One Health in practice highlight the potential but also the challenges of institutionalizing cooperation. We also discuss the promise and pitfalls of using complexity theory to tackle multifaceted problems, and consider how the One Health concept has been brought to bear on other issues, such as emerging new technologies. Ultimately, One Health is an important and worthwhile goal, and requires a debate that clarifies both the competing uses and the political nature of the project.

Parasites and biological invasions: parallels, interactions, and control

Species distributions are changing at an unprecedented rate owing to human activity. We examine how two key processes of redistribution - biological invasion and disease emergence - are interlinked. There are many parallels between invasion and emergence processes, and invasions can drive the spread of new diseases to wildlife. We examine the potential impacts of invasion and disease emergence, and discuss how these threats can be countered, focusing on biosecurity. In contrast with international policy on emerging diseases of humans and managed species, policy on invasive species and parasites of wildlife is fragmented, and the lack of international cooperation encourages individual parties to minimize their input into control. We call for international policy that acknowledges the strong links between emerging diseases and invasion risk.