Estimation of Covid-19 Prevalence Dynamics from Pooled Data

Estimating the prevalence of a disease, such as COVID-19, is necessary for evaluating and mitigating risks of its transmission. Estimates that consider how prevalence changes with time provide more information about these risks but are difficult to obtain due to the necessary survey intensity and commensurate testing costs. Motivated by a dataset on COVID-19, from the University of Notre Dame, we propose pooling and jointly testing multiple samples to reduce testing costs. A nonparametric, hierarchical Bayesian model is used to infer population prevalence from the pooled test results without needing to retest individuals from pools that test positive. This approach is shown to reduce uncertainty compared to individual testing at the same budget and to produce similar estimates compared to individual testing at a much higher budget through simulation studies and an analysis of COVID-19 infections at Notre Dame.

Fostering landscape immunity to protect human health: a science-based rationale for shifting conservation policy paradigms

Anthropogenic land use change is a major driver of zoonotic pathogen spillover from wildlife to humans. According to the land use-induced spillover model, land use change alters environmental conditions that in turn alter the dynamics between zoonotic pathogens and their wildlife hosts. Thus, in response to the global spread of the SARS-CoV-2 virus (the agent of COVID-19 disease), there have been renewed calls for landscape conservation as a disease preventive measure, including by the G7 Ministers responsible for Climate and the Environment. Landscape immunity, as a new construct, points to four paradigm shifts the world must favor to effectively mitigate pandemic risks. We provide a landscape immunity primer for policy makers and make the case for "world views" that place Homo sapiens within ecological systems, regard human health as an ecological service, prioritize investments in prevention, and apply ecological restoration to human health goals. Crisis is a conversation starter for reimagining and recommitting ourselves to what is most vital and generative. We urge world leaders to make the move to a nature-positive world.

Coronaviruses and Australian bats: A review in the midst of a pandemic

Australia's 81 bat species play vital ecological and economic roles via suppression of insect pests and maintenance of native forests through pollination and seed dispersal. Bats also host a wide diversity of coronaviruses globally, including several viral species that are closely related to SARS-CoV-2 and other emergent human respiratory coronaviruses. Although there are hundreds of studies of bat coronaviruses globally, there are only three studies of bat coronaviruses in Australian bat species, and no systematic studies of drivers of shedding. These limited studies have identified two betacoronaviruses and seven alphacoronaviruses, but less than half of Australian species are included in these studies and further research is therefore needed. There is no current evidence of spillover of coronaviruses from bats to humans in Australia, either directly or indirectly via intermediate hosts. The limited available data are inadequate to determine whether this lack of evidence indicates that spillover does not occur or occurs but is undetected. Conversely, multiple international agencies have flagged the potential transmission of human coronaviruses (including SARS CoV-2) from humans to bats, and the consequent threat to bat conservation and human health. Australia has a long history of bat research across a broad range of ecological and associated disciplines, as well as expertise in viral spillover from bats. This strong foundation is an ideal platform for developing integrative approaches to understanding bat health and sustainable protection of human health. © 2020 Journal Compilation