Safeguarding human health in the Anthropocene epoch: report of The Rockefeller Foundation–Lancet Commission on planetary health

The majority of human emerging infectious diseases are zoonotic, with viruses that originate in wild mammals of particular concern (for example, HIV, Ebola and SARS). Understanding patterns of viral diversity in wildlife and determinants of successful cross-species transmission, or spillover, are therefore key goals for pandemic surveillance programs. However, few analytical tools exist to identify which host species are likely to harbour the next human virus, or which viruses can cross species boundaries. Here we conduct a comprehensive analysis of mammalian host-virus relationships and show that both the total number of viruses that infect a given species and the proportion likely to be zoonotic are predictable. After controlling for research effort, the proportion of zoonotic viruses per species is predicted by phylogenetic relatedness to humans, host taxonomy and human population within a species range-which may reflect human-wildlife contact. We demonstrate that bats harbour a significantly higher proportion of zoonotic viruses than all other mammalian orders. We also identify the taxa and geographic regions with the largest estimated number of 'missing viruses' and 'missing zoonoses' and therefore of highest value for future surveillance. We then show that phylogenetic host breadth and other viral traits are significant predictors of zoonotic potential, providing a novel framework to assess if a newly discovered mammalian virus could infect people.

/pdf/host-and-viral-traits-predict-zoonotic-spillover-from-4mac9golh6.pdf

Host and viral traits predict zoonotic spillover from mammals

COVID-19 is a novel coronavirus with an outbreak of unusual viral pneumonia in Wuhan, China, and then pandemic. Based on its phylogenetic relationships and genomic structures the COVID-19 belongs to genera Betacoronavirus. Human Betacoronaviruses (SARS-CoV-2, SARS-CoV, and MERS-CoV) have many similarities, but also have differences in their genomic and phenotypic structure that can influence their pathogenesis. COVID-19 is containing single-stranded (positive-sense) RNA associated with a nucleoprotein within a capsid comprised of matrix protein. A typical CoV contains at least six ORFs in its genome. All the structural and accessory proteins are translated from the sgRNAs of CoVs. Four main structural proteins are encoded by ORFs 10, 11 on the one-third of the genome near the 3'-terminus. The genetic and phenotypic structure of COVID-19 in pathogenesis is important. This article highlights the most important of these features compared to other Betacoronaviruses.

Genotype and phenotype of COVID-19: Their roles in pathogenesis.

Viruses that originate in bats may be the most notorious emerging zoonoses that spill over from wildlife into domestic animals and humans. Understanding how these infections filter through ecological systems to cause disease in humans is of profound importance to public health. Transmission of viruses from bats to humans requires a hierarchy of enabling conditions that connect the distribution of reservoir hosts, viral infection within these hosts, and exposure and susceptibility of recipient hosts. For many emerging bat viruses, spillover also requires viral shedding from bats, and survival of the virus in the environment. Focusing on Hendra virus, but also addressing Nipah virus, Ebola virus, Marburg virus and coronaviruses, we delineate this cross-species spillover dynamic from the within-host processes that drive virus excretion to land-use changes that increase interaction among species. We describe how land-use changes may affect co-occurrence and contact between bats and recipient hosts. Two hypotheses may explain temporal and spatial pulses of virus shedding in bat populations: episodic shedding from persistently infected bats or transient epidemics that occur as virus is transmitted among bat populations. Management of livestock also may affect the probability of exposure and disease. Interventions to decrease the probability of virus spillover can be implemented at multiple levels from targeting the reservoir host to managing recipient host exposure and susceptibility.

https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2014.2124

Ecological dynamics of emerging bat virus spillover

Urbanization is characterized by rapid intensification of agriculture, socioeconomic change, and ecological fragmentation, which can have profound impacts on the epidemiology of infectious disease Here, we review current scientific evidence for the drivers and epidemiology of emerging wildlife-borne zoonoses in urban landscapes, where anthropogenic pressures can create diverse wildlife–livestock–human interfaces We argue that these interfaces represent a critical point for cross-species transmission and emergence of pathogens into new host populations, and thus understanding their form and function is necessary to identify suitable interventions to mitigate the risk of disease emergence To achieve this, interfaces must be studied as complex, multihost communities whose structure and form are dictated by both ecological and anthropological factors

Urbanization and Disease Emergence: Dynamics at the Wildlife–Livestock–Human Interface

Bats are the natural reservoirs of a number of high-impact viral zoonoses. We present a quantitative analysis to address the hypothesis that bats are unique in their propensity to host zoonotic viruses based on a comparison with rodents, another important host order. We found that bats indeed host more zoonotic viruses per species than rodents, and we identified life-history and ecological factors that promote zoonotic viral richness. More zoonotic viruses are hosted by species whose distributions overlap with a greater number of other species in the same taxonomic order (sympatry). Specifically in bats, there was evidence for increased zoonotic viral richness in species with smaller litters (one young), greater longevity and more litters per year. Furthermore, our results point to a new hypothesis to explain in part why bats host more zoonotic viruses per species: the stronger effect of sympatry in bats and more viruses shared between bat species suggests that interspecific transmission is more prevalent among bats than among rodents. Although bats host more zoonotic viruses per species, the total number of zoonotic viruses identified in bats (61) was lower than in rodents (68), a result of there being approximately twice the number of rodent species as bat species. Therefore, rodents should still be a serious concern as reservoirs of emerging viruses. These findings shed light on disease emergence and perpetuation mechanisms and may help lead to a predictive framework for identifying future emerging infectious virus reservoirs.

/pdf/a-comparison-of-bats-and-rodents-as-reservoirs-of-zoonotic-2lpbsia8uc.pdf

A comparison of bats and rodents as reservoirs of zoonotic viruses: are bats special?

Animal personality or temperament refers to individual differences in behaviour that are repeatable over time and across contexts. Personality has been linked to life-history traits, energetic traits and fitness, with implications for the evolution of behaviour. Personality has been quantified for a range of taxa (e.g., fish, songbirds, small mammals) but, so far, there has been little work on personality in bats, despite their diversity and potential as a model taxon for comparative studies. We used a novel environment test to quantify personality in little brown bats (Myotis lucifugus) and assess the short-term repeatability of a range of behaviours. We tested the hypothesis that development influences values of personality traits and predicted that trait values associated with activity would increase between newly volant, pre-weaning young-of-the-year (YOY) and more mature, self-sufficient YOY. We identified personality dimensions that were consistent with past studies of other taxa and found that these traits were repeatable over a 24-hour period. Consistent with our prediction, older YOY captured at a fall swarming site prior to hibernation had higher activity scores than younger YOY bats captured at a maternity colony, suggesting that personality traits vary as development progresses in YOY bats. Thus, we found evidence of short-term consistency of personality within individuals but with the potential for temporal flexibility of traits, depending on age.

/pdf/personality-variation-in-little-brown-bats-crv606uvd9.pdf

Personality Variation in Little Brown Bats

Burdock (Arctium spp.) is an invasive species from Eurasia, first reported in New England in 1638. It was common in Ontario by 1860, and is now considered an agricultural pest throughout its North American range (Royer and Dickinson 1999). Burdock's wide range can be attributed, in part, to the distinctive morphology of its seed casing, which has adhesive spines that readily attach to skin, fur, and feathers, enabling animal-based dispersal (Royer and Dickinson 1999). Burdock can pose a threat for small, flying vertebrates if the seed casing becomes entangled with the flight membrane of bats or the primary or secondary feathers of birds (for example, Lyon 1925; McNicholl 1988; Hager and others 2009). There are a number of published accounts of mortality for small birds found ensnared on Burdock including Ruby-throated Hummingbird (Archilochus colubris; McNicholl 1988; Nealen and Nealen 2000; Hinam and others 2004); Least Flycatcher (Empidonax minimus; Underwood and Underwood 2001; Hager and others 2009); Common Yellowthroat (Geothlypis trichas; Brown 1970); Blue-gray Gnatcatcher (Polioptila caerulea; Brewer 1994; McNicholl 1994); Ruby-crowned Kinglet (Regulus calendula; Van Damme 2005); and Golden-crowned Kinglet (Regulus satrapa; Dawe 1974), among others (for example, Burton 1994; Dean 1994; McNicholl 1994; Underwood and Underwood 2001). These accounts suggest that mortality due to Burdock may be relatively common for small birds (3.5-15.2 g; Van Damme 2005), especially since many similar events likely go unreported. Although mortality caused by Burdock has been most widely reported for small birds, Burdock may pose a similar threat for small bats. In 1892, approximately 12 bats, presumed to be Little Brown Bats (Myotis lucifugus) were found dead attached to Burdock in Illinois

Mary E. Timonin

Papers

A comparison of bats and rodents as reservoirs of zoonotic viruses: are bats special?

Personality Variation in Little Brown Bats

Silver-Haired Bats (Lasionycteris noctivagans) Found Ensnared on Burdock (Arctium minus)