More people, more cats, more parasites: Human population density and temperature variation predict prevalence of \u3ci\u3eToxoplasma gondii\u3c/i\u3e oocyst shedding in free-ranging domestic and wild felids

Toxoplasma gondii is a ubiquitous zoonotic parasite that can infect warm-blooded vertebrates, including humans. Felids, the definitive hosts, drive T. gondii infections by shedding the environmentally resistant stage of the parasite (oocysts) in their feces. Few studies characterize the role of climate and anthropogenic factors in oocyst shedding among free-ranging felids, which are responsible for the majority of environmental contamination. We determined how climate and anthropogenic factors influence oocyst shedding in free-ranging domestic cats and wild felids using generalized linear mixed models. T. gondii oocyst shedding data from 47 studies were systematically reviewed and compiled for domestic cats and six wild felid species, encompassing 256 positives out of 9,635 total fecal samples. Shedding prevalence in domestic cats and wild felids was positively associated with human population density at the sampling location. Larger mean diurnal temperature range was associated with more shedding among domestic cats and warmer temperature in the driest quarter was associated with lower oocyst shedding in wild felids. Increasing human population density and temperature fluctuation can exacerbate environmental contamination with the protozoan parasite T. gondii. Management of free-ranging domestic cats could lower the burden of environmental oocysts due to their large population sizes and affinity with human settlements

Haemosporidian parasite diversity in an under-surveyed Australian avifauna

Haemosporidian parasites of birds are geographically widespread, have been detected in a phylogenetically diverse array of hosts, and have been the focus of extensive research due to both their impacts on birds and their similarity to vector-borne diseases of humans. Advances in molecular diagnostic tools have created a greater awareness of the genetic diversity of haemosporidian infections. Yet in spite of their more or less global distribution, comparatively little is known about the haemosporidians affecting birds in Australia. We screened blood from 889 birds (23 species) for haemosporidian blood parasite infections during the 2019 breeding season at Brookfield Conservation Park, South Australia. We examined the genetic (lineage) diversity of haemosporidian infections in this behaviorally and ecologically diverse host assemblage and examined the congruence between parasite and host phylogenies. We identified seven Haemoproteus mitochondrial cytochrome b lineages, five of which were novel. Four birds had simultaneous co-infections by two Haemoproteus lineages each. The Haemoproteus lineages clustered at the host family level. Two Plasmodium lineages were also identified, each of which had been previously detected in different avian host species in Australasia. We did not detect any Leucocytozoon infections in our sample. This study supplies critical baseline data on host–parasite associations in a poorly-surveyed geographic region

Environmental transmission of Toxoplasma gondii: Oocysts in water, soil and food

Toxoplasma gondii is a zoonotic protozoan parasite that can cause morbidity and mortality in humans, domestic animals, and terrestrial and aquatic wildlife. The environmentally robust oocyst stage of T. gondii is fundamentally critical to the parasite\u27s success, both in terms of its worldwide distribution as well as the extensive range of infected intermediate hosts. Despite the limited definitive host species (domestic and wild felids), infections have been reported on every continent, and in terrestrial as well as aquatic environments. The remarkable resistance of the oocyst wall enables dissemination of T. gondii through watersheds and ecosystems, and long-term persistence in diverse foods such as shellfish and fresh produce. Here, we review the key attributes of oocyst biophysical properties that confer their ability to disseminate and survive in the environment, as well as the epidemiological dynamics of oocyst sources including domestic and wild felids. This manuscript further provides a comprehensive review of the pathways by which T. gondii oocysts can infect animals and people through the environment, including in contaminated foods, water or soil. We conclude by identifying critical control points for reducing risk of exposure to oocysts as well as opportunities for future synergies and new directions for research aimed at reducing the burden of oocyst-borne toxoplasmosis in humans, domestic animals, and wildlife

Using art and story to explore how primary school students in rural Tanzania understand planetary health: a qualitative analysis

Background The global planetary health community increasingly recognises the need to prepare students to investigate and address connections between environmental change and human health. As we strive to support education on planetary health themes for students of all ages, understanding students’ concepts of linkages between the health of people and animals, and their shared environments might advance educational approaches. Children living in villages bordering Ruaha National Park in Iringa Region, Tanzania, have direct experience of these connections as they share a water-stressed but biodiverse environment with domestic animals and wildlife. Livelihoods in these villages depend predominantly on crop and livestock production, including extensive pastoralist livestock keeping. Through qualitative research, we aim to explore and describe Tanzanian primary school students’ understanding of connections between human health and the environment

Accuracy of COVID-19 Relevant Knowledge among Youth: Number of Information Sources Matters

Can comics effectively convey scientific knowledge about COVID-19 to youth? What types and how many sources of information did youth have about COVID-19 during the pandemic? How are sources of information associated with accurate COVID-19 knowledge? To answer these questions, we surveyed youth in grades 5–9 in a Midwestern United States school district in the winter of 2020–2021. The online survey used measures of COVID-19 knowledge and sources, with an embedded experiment on COVID-19 relevant comics. Guided by an integrated science capital and just-in-time health and science information acquisition model, we also measured level of science capital, science identity, and utility of science for health and society. The school district protocol required parental consent for participation; 264 of ~15,000 youth participated. Youth were randomly assigned one of four comic conditions before receiving an online survey. Results indicate that, similar to knowledge gains in comic studies on other science topics, reading the comics was associated with 7 to 29% higher accuracy about COVID-19. We found that youth reported getting information about COVID-19 from between 0–6 sources including media, family, friends, school, and experts. The bivariate positive association of news versus other sources with accuracy of knowledge did not persist in the full model, yet the positive association of a higher number of sources and accuracy did persist in the multivariate models. The degree of valuing the utility of science for their health moderated the number of sources to accuracy association. Those with less value on science for health had a stronger positive association of number of sources and accuracy in COVID-19 knowledge. We conclude that during a pandemic, even with health and science information ubiquitous in the news media, increasing youth access to a variety of accurate sources of information about science and health can increase youth knowledge

Educating pastoralists and extension officers on diverse livestock diseases in a changing environment in Tanzania

East African pastoralists and their livestock are vulnerable to alterations in resource availability and disease transmission and frequently face poor access to livestock health services. Government veterinarians tasked with guiding health services must prioritize livestock health risks and allocate limited resources across disparate ecosystems with different disease threats. To identify livestock diseases of concern and strategies for improving herd health and resilience, we conducted community focus groups with pastoralists and interviewed pastoralist household leaders, village extension officers, and government veterinary officials in south-central Tanzania, an area experiencing rapid population growth and environmental change. All participants discussed pastoralist access to livestock health services, livestock disease priorities, and means to improve livestock health. Perceptions of diseases of importance differed among pastoralists, extension officers, and government veterinarians. Spatial differences in diseases of concern among study area pastoralists emphasized the need for locally adaptable livestock health service delivery. Although pastoralist strategies to improve livestock health differed by ethnic group, many pastoralists as well as extension officers and government veterinarians identified livestock health education and training for pastoralists and extension officers as a critical need. Policies designed at the regional, rather than the local, level may not reflect the disease concerns of the entire area. To effectively address veterinary health problems and make livestock herds more resilient to environmental change, conditions at the local level must be considered. Education targeted to pastoralist households and extension officers could achieve greater flexibility in the livestock health system and provide more reliable information about local conditions for governmental policymakers

Developing Pandemic Comics for Youth Audiences

In spring 2020 our team received funding from the Rapid Response Research program of the National Science Foundation to develop comics that would help youth understand the COVID-19 pandemic. Our project built on a decade of expertise creating comics about the biology of viruses. In collaboration with virologists and artists, we developed three comic stories about COVID-19 during the pandemic and posted them on-line during the last half of 2020. The fictional narratives address fundamental issues in biology, virology, and network science, in order to help readers understand the complexities of living through a viral pandemic. The stories focus on three themes: the biology and social context of the COVID-19 virus; the relationship of wild animals, particularly bats, to the pandemic; and the impact of the pandemic on Tribal communities. We describe the challenges of comic development during the pandemic and the feedback from youth on whether the comics were appealing, interesting, and understandable. The stories were posted on worldofviruses.unl.edu and are published by the University of Nebraska Press as the book, C’RONA Pandemic Comics, with essays for youth about the virus and the pandemic

Quantitative Risk Assessment of Oocyst Versus Bradyzoite Foodborne Transmission of \u3ci\u3eToxoplasma gondii\u3c/i\u3e in Brazil

Toxoplasma gondii is a globally distributed zoonotic protozoan parasite. Infection with T. gondii can cause congenital toxoplasmosis in developing fetuses and acute outbreaks in the general population, and the disease burden is especially high in South America. Prior studies found that the environmental stage of T. gondii, oocysts, is an important source of infection in Brazil; however, no studies have quantified this risk relative to other parasite stages. We developed a Bayesian quantitative risk assessment (QRA) to estimate the relative attribution of the two primary parasite stages (bradyzoite and oocyst) that can be transmitted in foods to people in Brazil. Oocyst contamination in fruits and greens contributed significantly more to overall estimated T. gondii infections than bradyzoite-contaminated foods (beef, pork, poultry). In sensitivity analysis, treatment, i.e., cooking temperature for meat and washing efficiency for produce, most strongly affected the estimated toxoplasmosis incidence rate. Due to the lack of regional food contamination prevalence data and the high level of uncertainty in many model parameters, this analysis provides an initial estimate of the relative importance of food products. Important knowledge gaps for oocyst-borne infections were identified and can drive future studies to improve risk assessments and effective policy actions to reduce human toxoplasmosis in Brazil

Panarchy theory for convergence

Coping with surprise and uncertainty resulting from the emergence of undesired and unexpected novelty or the sudden reorganization of systems at multiple spatiotemporal scales requires both a scientific process that can incorporate diverse expertise and viewpoints, and a scientific framework that can account for the structure and dynamics of interacting social-ecological systems (SES) and the inherent uncertainty of what might emerge in the future. We argue that combining a convergence scientific process with a panarchy framework provides a pathway for improving our understanding of, and response to, emergence. Emergent phenomena are often unexpected (e.g., pandemics, regime shifts) and can be highly disruptive, so can pose a significant challenge to the development of sustainable and resilient SES. Convergence science is a new approach promoted by the U.S. National Science Foundation for tackling complex problems confronting humanity through the integration of multiple perspectives, expertise, methods, tools, and analytical approaches. Panarchy theory is a framework useful for studying emergence, because it characterizes complex systems of people and nature as dynamically organized and structured within and across scales of space and time. It accounts for the fundamental tenets of complex systems and explicitly grapples with emergence, including the emergence of novelty, and the emergent property of social-ecological resilience. We provide an overview of panarchy, convergence science, and emergence. We discuss the significant data and methodological challenges of using panarchy in a convergence approach to address emergent phenomena, as well as state-of-the-art methods for overcoming them. We present two examples that would benefit from such an approach: climate change and its impacts on social-ecological systems, and the relationships between infectious disease and social-ecological systems