Modelling the spead of Sphaerothecum destruens, a generalist fungal pathogen.

Humans have altered the global landscape with agriculture, urban development and international trade, and the incidence of emerging infectious diseases (EIDs) has increased as a result. Pathogens can emerge in new areas as a direct result of global transport trade or indirectly due to climate–mediated shifts in parasite geographic range. These pathogens can cause considerable ecological and economic damage, as they accelerate biodiversity loss and threaten global food security. Furthermore, the inherent characteristics of pathogens allow their rapid evolution, intensifying their potential threat. Fungi and fungal-like pathogens are an increasing component of EIDs with highly opportunistic features. One group of these pathogens on the animal-fungal boundary is the Mesomycetozoea, a group which has raised ecological concerns for a range of susceptible host species including birds, amphibians and mammals. To be able to mitigate the impacts of these pathogens effectively, their dynamics and drivers must be better understood. Using the only Mesomycetozoea fungal species that has been cultured to date, the generalist pathogen Sphaerothecum destruens, empirical data on infectivity and pathogen life cycle were used in several epidemiological models to explore how a fungal-like generalist is transmitted within different host communities. First, a single host system was created using the available empirical data. This demonstrated that multiple saturation functions were needed to parameterise the model accurately, and identified incubation and recovery rates as drivers of epidemics. The parameter values obtained from the single-host models enabled the characterisation of mathematical relationships between different parameters, a task which can be difficult in epidemiology. Following this, a multi-host model was used to examine pathogen establishment in different communities. The roles of community structure and composition were explored, including the influence of competitive interactions between host species. Host density, proximity between communities, the competitive interactions between species, and the persistence of free-living pathogen propagules were identified as important factors in disease emergence and community survival. Environmental transmission was a key pathway for pathogen establishment. Finally, the evolution of S. destruens’ virulence was explored in different conditions and for various transmission strategies. Direct contact and environmental uptake rates were key determinants of pathogen evolutionary stable strategy. Host eradication and selective restocking were evaluated as disease management techniques, examining the advantages and possible repercussions of each approach in light of the pathogen’s ecological and evolutionary dynamics. Mathematical models have been crucial in expanding ecological and epidemiological knowledge in other pathogens, allowing the exploration of diverse conditions and hypotheses about disease dynamics. The reliability of the results and their applicability were greatly enhanced by the inclusion of empirical data, giving this research substantial advantage in the robustness of model outputs. This work provided new insights on how fungal and fungal-like pathogens are transmitted and the risks of establishment in different populations, and can be applied to similar emerging pathogens, especially those that are fungi and fungal-like

The influence of predation on community resilience to disease

1. Outbreaks of generalist pathogens are influenced by host community structure, including population density and species diversity. Within host communities predation can influence pathogen transmission rates, prevalence and impacts. However, the influence of predation on community resilience to outbreaks of generalist pathogens are not fully understood. 2. The role of predation on host community resilience to disease was assessed using an epidemiological multi-host Susceptible-Exposed-Infectious-Recovered (SEIR) model. Sphaerothecum destruens, an emerging fungal-like generalist pathogen, was used as a model pathogen. Six cyprinid and salmonid fishes, including an asymptomatic carrier, were selected as model hosts that are known to be impacted by S. destruens, and they were used within a model host community. 3. Pathogen release into the host community was via introduction of the asymptomatic carrier. Mortality from infection, pathogen incubation rate, and host recovery rate were set to a range of evidence-based values in each species and were varied in secondary consumers to predict top-down effects of infection on the resilience of a host community. Predation pressure within the fish community was varied to test its effects on infection prevalence and host survival in the community. 4. Model predictions suggested that predation of the asymptomatic hosts by fishes in the host community was insufficient to eliminate S. destruens. S. destruens persisted in the community due to its rapid transmission from the asymptomatic host to susceptible host fishes. Following transmission, pathogen prevalence in the community was driven by transmission within and between susceptible host fishes, indicating low host community resilience. However, introducing low densities of a highly specific piscivorous fish into the community to predate asymptomatic hosts could limit pathogen prevalence in the host community, thus increasing resilience. 5. The model predictions indicate that whilst resilience to this generalist pathogen in the host community was low, this could be increased using management interventions. The results suggest that this model has high utility for predicting community resilience to disease and thus can be applied to other generalist parasites to determine risks of disease emergence

Discussion of "Evidence-based health informatics:how do we know what we know?"

This article is part of a For-Discussion-Section of Methods of Information in Medicine about the paper "Evidence-based Health Informatics: How Do We Know What We Know?" written by Elske Ammenwerth [1]. It is introduced by an editorial. This article contains the combined commentaries invited to independently comment on the Ammenwerth paper. In subsequent issues the discussion can continue through letters to the editor. With these comments on the paper "Evidence-based Health Informatics: How do we know what we know?", written by Elske Ammenwerth [1], the journal seeks to stimulate a broad discussion on the challenges of evaluating information processing and information technology in health care. An international group of experts has been invited by the editor of Methods to comment on this paper. Each of the invited commentaries forms one section of this paper.11 page(s

Species Mortality data: infection with S. destruens

Mortality data of fish species infected with Sphaerothecum destruens

Evidence-based health informatics as the foundation for the COVID-19 response: a joint call for action

Background: As a major public health crisis, the novel coronavirus disease 2019 (COVID-19) pandemic demonstrates the urgent need for safe, effective, and evidence-based implementations of digital health. The urgency stems from the frequent tendency to focus attention on seemingly high promising digital health interventions despite being poorly validated in times of crisis. Aim: In this paper, we describe a joint call for action to use and leverage evidence- based health informatics as the foundation for the COVID-19 response and public health interventions. Tangible examples are provided for how the working groups and special interest groups of the International Medical Informatics Association (IMIA) are helping to build an evidence-based response to this crisis. Methods: Leaders of working and special interest groups of the IMIA, a total of 26 groups, were contacted via e-mail to provide a summary of the scientific-based efforts taken to combat COVID-19 pandemic and participate in the discussion toward the creation of this manuscript. A total of 13 groups participated in this manuscript. Results: Various efforts were exerted by members of IMIA including (1) developing evidence-based guidelines for the design and deployment of digital health solutions during COVID-19; (2) surveying clinical informaticians internationally about key digital solutions deployed to combat COVID-19 and the challenges faced when implementing and using them; and (3) offering necessary resources for clinicians about the use of digital tools in clinical practice, education, and research during COVID-19. Discussion: Rigor and evidence need to be taken into consideration when designing, implementing, and using digital tools to combat COVID-19 to avoid delays and unforeseen negative consequences. It is paramount to employ a multidisciplinary approach for the development and implementation of digital health tools that have been rapidly deployed in response to the pandemic bearing in mind human factors, ethics, data privacy, and the diversity of context at the local, national, and international levels. The training and capacity building of front-line workers is crucial and must be linked to a clear strategy for evaluation of ongoing experiences