WildHealthNet: Supporting the development of sustainable wildlife health surveillance networks in Southeast Asia.

Wildlife and wildlife interfaces with people and livestock are essential surveillance targets to monitor emergent or endemic pathogens or new threats affecting wildlife, livestock, and human health. However, limitations of previous investments in scope and duration have resulted in a neglect of wildlife health surveillance (WHS) systems at national and global scales, particularly in lower and middle income countries (LMICs). Building on decades of wildlife health activities in LMICs, we demonstrate the implementation of a locally-driven multi-pronged One Health approach to establishing WHS in Cambodia, Lao PDR and Viet Nam under the WildHealthNet initiative. WildHealthNet utilizes existing local capacity in the animal, public health, and environmental sectors for event based or targeted surveillance and disease detection. To scale up surveillance systems to the national level, WildHealthNet relies on iterative field implementation and policy development, capacity bridging, improving data collection and management systems, and implementing context specific responses to wildlife health intelligence. National WHS systems piloted in Cambodia, Lao PDR, and Viet Nam engaged protected area rangers, wildlife rescue centers, community members, and livestock and human health sector staff and laboratories. Surveillance activities detected outbreaks of H5N1 highly pathogenic avian influenza in wild birds, African swine fever in wild boar (Sus scrofa), Lumpy skin disease in banteng (Bos javanicus), and other endemic zoonotic pathogens identified as surveillance priorities by local stakeholders. In Cambodia and Lao PDR, national plans for wildlife disease surveillance are being signed into legislation. Cross-sectoral and trans-disciplinary approaches are needed to implement effective WHS systems. Long-term commitment, and paralleled implementation and policy development are key to sustainable WHS networks. WildHealthNet offers a roadmap to aid in the development of locally-relevant and locally-led WHS systems that support the global objectives of the World Organization for Animal Health's Wildlife Health Framework and other international agendas.

Seasonal shedding of coronavirus by straw-colored fruit bats at urban roosts in Africa.

The straw-colored fruit bat (Eidolon helvum) is a pteropodid whose conservation is crucial for maintaining functional connectivity of plant populations in tropical Africa. Land conversion has pushed this species to adapt to roosting in urban centers across its range. These colonies often host millions of individuals, creating intensive human-bat contact interfaces that could facilitate the spillover of coronaviruses shed by these bats. A better understanding of coronavirus dynamics in these roosts is needed to identify peak times of exposure risk in order to propose evidence-based management that supports safe human-bat coexistence, as well as the conservation of this chiropteran. We studied the temporal patterns of coronavirus shedding in E. helvum, by testing thousands of longitudinally-collected fecal samples from two spatially distant urban roosts in Ghana and Tanzania. Shedding of coronaviruses peaked during the second part of pup weaning in both roosts. Assuming that coronavirus shedding is directly related to spillover risk, our results indicate that exposure mitigation should target reducing contact between people and E. helvum roosts during the pup "weaning" period. This recommendation can be applied across the many highly-populated urban sites occupied by E. helvum across Africa.

Wildlife rehabilitation centers as a potential source of transmission of SARS-CoV-2 into native wildlife of Latin America.

The COVID-19 pandemic has impacted the entire world, causing a great number of mortality of humans and affecting the economy, while conservation efforts are finally recognized to prevent further pandemics. The wildlife rehabilitation centers (WRCs) play a relevant role in animal welfare; nevertheless, they also represent an imminent risk of pathogen transmission between humans-to-animals and between animals. Moreover, WRCs could spread pathogens into natural habitats through the reintroduction of infectious individuals. These biosafety concerns at WRCs may increase as the economic and social impact of the COVID-19 extends. We explored the current situation of Latin American WRCs under the COVID-19 pandemic to determine the feasibility of SARS-CoV-2 introduction, amplification, and spread within these institutions. We surveyed WRCs from eight Latin American countries. We found that pandemic is affecting these institutions in many aspects: workers with symptoms compatible with COVID-19, reduced economic resources, and lack of information and support from governmental authorities. These have forced WRCs to reduce the workforce, veterinary visits, and animal food rations and to increase the number of animals released. This scenario generates a risky environment for the transmission of SARS-CoV-2, especially for felids, mustelids, and non-human primates. Therefore, it is imperative to respect quarantine periods, monitor incoming patients, increase biosecurity measures, develop and apply guidelines and recommendations for the protection of personnel and biosafety of enclosures and instruments. It is of utmost importance the proper and safer reintroduction of recovered wildlife.

La pandemia de COVID­19 ha impactado mundialmente, provocando una alta mortalidad en humanos y afectando la economía, resaltando la importancia de los esfuerzos de conservación para prevenir nuevas pandemias. Los centros de rehabilitación de vida silvestre juegan un papel relevante en el bienestar animal, sin embargo, también representan un riesgo inminente de transmisión de patógenos entre humanos a animales y entre animales. Además, los centros de rehabilitación de vida silvestre podrían propagar patógenos a hábitats naturales mediante la reintroducción de individuos infecciosos. Estas preocupaciones de bioseguridad en centros de rehabilitación de vida silvestre pueden aumentar a medida que se extiende el impacto económico y social del COVID­19. Exploramos la situación actual de centros de rehabilitación de vida silvestre latinoamericanos durante la pandemia de COVID­19 para determinar la viabilidad de la introducción, amplificación y propagación del SARS­CoV­2 dentro de estas instituciones. Encuestamos centros de rehabilitación de vida silvestre de ocho países latinoamericanos y encontramos que la pandemia está afectando a estas instituciones en muchos aspectos: trabajadores con síntomas compatibles con COVID­19, recursos económicos reducidos y falta de información y apoyo de las autoridades gubernamentales. Estos han obligado a centros de rehabilitación de vida silvestre a reducir la mano de obra, las visitas veterinarias y las raciones de alimentos para animales, así como aumentar el número de animales liberados. Este escenario genera un entorno de riesgo para la transmisión del SARS­CoV­2, especialmente para félidos, mustélidos y primates no humanos. Por lo tanto, es imperativo respetar los períodos de cuarentena, monitorear a los pacientes que ingresan, incrementar las medidas de bioseguridad, desarrollar y aplicar lineamientos y recomendaciones para la protección del personal y la bioseguridad. Es de suma importancia la reintroducción adecuada y segura de la vida silvestre recuperada.

Reproduction of East-African bats may guide risk mitigation for coronavirus spillover.

BACKGROUND: Bats provide important ecosystem services; however, current evidence supports that they host several zoonotic viruses, including species of the Coronaviridae family. If bats in close interaction with humans host and shed coronaviruses with zoonotic potential, such as the Severe Acute Respiratory Syndrome virus, spillover may occur. Therefore, strategies aiming to mitigate potential spillover and disease emergence, while supporting the conservation of bats and their important ecological roles are needed. Past research suggests that coronavirus shedding in bats varies seasonally following their reproductive cycle; however, shedding dynamics have been assessed in only a few species, which does not allow for generalization of findings across bat taxa and geographic regions. METHODS: To assess the generalizability of coronavirus shedding seasonality, we sampled hundreds of bats belonging to several species with different life history traits across East Africa at different times of the year. We assessed, via Bayesian modeling, the hypothesis that chiropterans, across species and spatial domains, experience seasonal trends in coronavirus shedding as a function of the reproductive cycle. RESULTS: We found that, beyond spatial, taxonomic, and life history differences, coronavirus shedding is more expected when pups are becoming independent from the dam and that juvenile bats are prone to shed these viruses. CONCLUSIONS: These findings could guide policy aimed at the prevention of spillover in limited-resource settings, where longitudinal surveillance is not feasible, by identifying high-risk periods for coronavirus shedding. In these periods, contact with bats should be avoided (for example, by impeding or forbidding people access to caves). Our proposed strategy provides an alternative to culling - an ethically questionable practice that may result in higher pathogen levels - and supports the conservation of bats and the delivery of their key ecosystem services.

Assessing the role of dens in the spread, establishment and persistence of sarcoptic mange in an endangered canid.

Sarcoptic mange is a skin disease caused by the mite Sarcoptes scabiei that can devastate populations of wild species. S. scabiei can survive off-host and remain infective for specific periods. In den-dwelling species, dislodged mites could be protected from the environmental conditions that impair their survival thus supporting pathogen transmission. To assess the potential role of dens in the spread, establishment, and persistence of sarcoptic mange in a population of hosts, we constructed an agent-based model of the endangered San Joaquin kit fox (SJKF; Vulpes macrotis mutica) population in Bakersfield, California, that explicitly considered the denning ecology and behavior of this species. We focused on this SJKF urban population because of their vulnerability and because a sarcoptic mange epizootic is currently ongoing. Further, SJKF is a social species that lives in family groups year-round and contact between individuals from different family groups is rare, but they will occupy the same dens intermittently. If mites remain infective in dens, they could support intra-family disease transmission via direct (den sharing) and indirect (contaminated den) contact, but also inter-family transmission if susceptible individuals from different families occupy contaminated dens. Simulations showed that den-associated transmission significantly increases the chances for the mite to spread, to establish and to persist. These findings hold for different within-den S. scabiei off-host survival periods assessed. Managers dealing with S. scabiei in this species as well as in other den-dwelling species should consider den-associated transmission as they could be targeted as part of the control strategies against this mite.

Evidence supporting that human-subsidized free-ranging dogs are the main cause of animal losses in small-scale farms in Chile.

We surveyed professionals from the Chilean Ministry of Agriculture working with small-scale farmers to characterize the attacks of free-ranging dogs across Chile. Nationwide, in a single year, free-ranging dogs attacked 25% of the ca. 8500 farms included in the survey, killing or injuring about 10 000 small ruminants. These dogs were ranked as the main cause of animal losses for small-scale farmers, representing a threat to the livelihoods of this vulnerable group. Further, free-ranging dogs attacking small ruminants were considered as human-subsidized, since they would be recruited by irresponsible ownership and abandonment from urban centers. This is the first national assessment reporting that human-subsidized dogs are a main threat to livestock rearing. Policies to control populations of these animals should target their anthropogenic origin as well as cultural shifts in dog ownership and animal welfare. While these policies may be effective mid- to long-term approaches, short-term actions may also be needed.

Overwintering of West Nile virus in a bird community with a communal crow roost.

In temperate climates, transmission of West Nile virus (WNV) is detectable rarely during the coldest months (late fall through early spring), yet the virus has reappeared consistently during the next warm season. Several mechanisms may contribute to WNV persistence through winter, including bird-to-bird transmission among highly viremic species. Here we consider whether, under realistic scenarios supported by field and laboratory evidence, a winter bird community could sustain WNV through the winter in the absence of mosquitoes. With this purpose we constructed a deterministic model for a community of susceptible birds consisting of communally roosting crows, raptors and other birds. We simulated WNV introduction and subsequent transmission dynamics during the winter under realistic initial conditions and model parameterizations, including plausible contact rates for roosting crows. Model results were used to determine whether the bird community could yield realistic outbreaks that would result in WNV infectious individuals at the end of the winter, which would set up the potential for onward horizontal transmission into summer. Our findings strongly suggest that winter crow roosts could allow for WNV persistence through the winter, and our model results provide synthesis to explain inconclusive results from field studies on WNV overwintering in crow roosts.

Devastating Transboundary Impacts of Sea Star Wasting Disease on Subtidal Asteroids.

Sea star wasting disease devastated intertidal sea star populations from Mexico to Alaska between 2013-15, but little detail is known about its impacts to subtidal species. We assessed the impacts of sea star wasting disease in the Salish Sea, a Canadian / United States transboundary marine ecosystem, and world-wide hotspot for temperate asteroid species diversity with a high degree of endemism. We analyzed roving diver survey data for the three most common subtidal sea star species collected by trained volunteer scuba divers between 2006-15 in 5 basins and on the outer coast of Washington, as well as scientific strip transect data for 11 common subtidal asteroid taxa collected by scientific divers in the San Juan Islands during the spring/summer of 2014 and 2015. Our findings highlight differential susceptibility and impact of sea star wasting disease among asteroid species populations and lack of differences between basins or on Washington's outer coast. Specifically, severe depletion of sunflower sea stars (Pycnopodia helianthoides) in the Salish Sea support reports of major declines in this species from California to Alaska, raising concern for the conservation of this ecologically important subtidal predator.

Elevation and vegetation determine Cryptosporidium oocyst shedding by yellow-bellied marmots (Marmota flaviventris) in the Sierra Nevada Mountains.

Wildlife are increasingly recognized as important biological reservoirs of zoonotic species of Cryptosporidium that might contaminate water and cause human exposure to this protozoal parasite. The habitat range of the yellow-bellied marmot (Marmota flaviventris) overlaps extensively with the watershed boundaries of municipal water supplies for California communities along the foothills of the Sierra Nevada. We conducted a cross-sectional epidemiological study to estimate the fecal shedding of Cryptosporidium oocysts by yellow-bellied marmots and to quantify the environmental loading rate and determine risk factors for Cryptosporidium fecal shedding in this montane wildlife species. The observed proportion of Cryptosporidium positive fecal samples was 14.7% (33/224, positive number relative to total number samples) and the environmental loading rate was estimated to be 10,693 oocysts animal(-1) day(-1). Fecal shedding was associated with the elevation and vegetation status of their habitat. Based on a portion of the 18s rRNA gene sequence of 2 isolates, the Cryptosporidium found in Marmota flaviventris were 99.88%-100% match to multiple isolates of C. parvum in the GenBank.