Thematic Session 5 - Disease Ecology

You are here

Thematic Session 5

Disease Ecology

Tuesday 9 February 2021 | 10:00-12:00 hrs


LINK TO ZOOM MEETING: Will Follow soon.


10:00 – 10:05 Introduction by the session chairs - Dr Thijs Frenken (Postdoc Aquatic Ecology @ Netherlands Institute of Ecology) & Dr Dedmer van de Waal (Senior Researcher Aquatic Ecology @ Netherlands Institute of Ecology)
10:05 – 10:20 KEYNOTE LECTURE | Effects of global change on parasites & diseases
David Thieltges @ Coastal Systems, Royal Netherlands Institute for Sea Research (NIOZ) & GELIFES, University of Groningen

​Ecosystems are facing a plethora of global environmental changes and it is increasingly recognised that those will also affect parasites and diseases of humans and wildlife. An ecological perspective on diseases has proven to be helpful in understanding the underlying mechanisms and led to the rise of disease ecology as a discipline. This presentation will provide a conceptual umbrella on how global change affects parasites and diseases and will thus set the stage for the contributions in the session. However, it will also highlight the difficulties in identifying universal patterns and making predictions given the complexity and diversity of parasite-host interactions.
10:20 – 10:30 Novel Arctic Micromonas polaris viruses and the influence of temperature and irradiance on virus-host interactions.
Tristan Biggs @ Department of Marine Microbiology and Biogeochemistry, Royal Netherlands Institute for Sea Research (NIOZ)

Arctic marine ecosystems are undergoing global warming induced changes in temperature and light, consequently predicted to benefit smaller-sized phytoplankton. Despite the ecological importance of viruses, little is known about how environmental change will affect virus-host interactions. We performed the first isolation and characterisation of a polar algal virus, and examined the effect of environmental change on virus production and infectivity. Results indicate that enhanced temperature impacted virus production positively and low light negatively. The effect of temperature (-20 to 7°C) on virus infectivity was strain-specific. Our results demonstrate that changing environmental conditions strongly affect Arctic phytoplankton population dynamics and diversity.
10:30 – 10:40 Parasites grow faster in faster growing hosts and at warmer temperatures
Boris W. Berkhout @ University of Leicester

Parasite fitness depends on host quality, yet parasites reduce host fitness, generating a so-called evolutionary arms-race. The cestode Schistocephalus solidus suppresses the immune response and egg production of stickleback (Gasterosteus aculeatus) hosts. The parasites grow faster at warmer temperatures, but how this affects the growth of sticklebacks is unknown. Through analysis of published data, we confirm that hosts and parasites grow faster at warmer temperatures and that parasites grow bigger in larger hosts. Additionally, parasites stronger reduce host growth at warmer temperatures. Therefore, under elevated temperature climate scenarios, the parasite may have the upper hand in the struggle for resources.
10:40 – 10:50 Changing elemental cycles, stoichiometric mismatches, and consequences for pathogens of primary producers
Thijs Frenken @ Aquatic Ecology, Netherlands Institute of Ecology

Human-induced changes in biogeochemical cycles alter the availability of carbon, nitrogen and phosphorus in the environment, leading to changes in the stoichiometry of primary producers. By using the framework of ecological stoichiometry we generate hypotheses and assess empirical evidence about how changes in elemental ratios, subsequently, alter the degree of stoichiometric mismatch between primary producer-hosts and their pathogens, with consequences for pathogen performance. We argue that ecological stoichiometry provides a predictive framework for future disease incidence under scenarios of changing biogeochemical cycles.
10:50 – 11:10 Joint coffee / tea break and time to socialise within your breakout room
11:10 – 11:20 Environmental pollution drives parasite infection in three-spined stickleback (Gasterosteus aculeatus)
Io Deflem @ Laboratory of Biodiversity and Evolutionary Genomics, KU Leuven

Anthropogenic environmental change is one of the major drivers of parasite infection dynamics in the wild. We examined how environmental and spatial variation influences parasite infection and condition in three-spined stickleback across a riverine landscape with varying levels of pollution. Parasite infection levels responded linearly to anthropogenic stressors. Excess nutrient levels (i.e. nitrogen and phosphate) positively affected infection with ectoparasites with horizontal transmission, but not species that infect their host through the food web. Host condition did not depend on anthropogenic disturbance and did not mediate the effect of environmental pollution on parasite infection.
11:20 – 11:30 Reservoir rodent host population dynamics drive wildlife-originated zoonotic infections in humans
Mahdi Aminikhah @ Department of Ecology and Genetics, University of Oulu

Rodents host an abundance of zoonotic pathogens that pose a risk to human health. Rodent population dynamics affect the infection dynamics of rodent-borne diseases, such as diseases caused by hantaviruses. However, the dependency of infection dynamics of rodent-associated tick-borne diseases, such as Lyme borreliosis (LB), on rodent population dynamics have gained limited attention. We quantify the associations among fluctuations in rodent density, weather (North Atlantic Oscillation), and LB and Puumala Orthohantavirus (PUUV) infections by using 25-year time series in Finland. Bank vole abundance as well as LB and PUUV infections in humans showed approximately 3-year cycles. Directly transmitted PUUV infections followed the bank vole host abundance with two-month time lag, whereas tick-transmitted LB was associated with bank vole abundance approximately 12 and 24 months earlier. Our results indicate that not only human risk to acquire PUUV, but also LB is associated with multiannual reservoir rodent host population fluctuations.
11:30 – 11:40 Predicting hotspots of forest pest invasions
Robbert Timothy van den Dool @ Centre for Crop Systems Analysis, Wageningen University

Policy makers and plant protection agencies are interested in knowing which locations are at increased risk of invasion by alien forest pests. As part of my PhD, I am developing a modelling approach to predict such hot spots of invasion risk. The model is built using historic data of past invasions and environmental characteristics of the European landscape to model the relative risk that a pest newly establishes at a location due to entry from outside the EU. This approach models probability density functions in a maximum likelihood framework with allowance for sampling bias, and correlated variables using copula modelling.
11:40 – 11:55 General discussion and wrap up of the session