Biology subjects

Dellar, M.

Publications and source records attributed to Dellar, M..

3 recordsLinked to original sources

bioRxiv2025

Implications of future change scenarios for mosquito-borne disease transmission in the Netherlands

BackgroundMosquito-borne virus transmission is shaped by its ecological context, including land use, climate, and population dynamics. Future changes in these factors may therefore affect the risk and intensity of Usutu virus (USUV) and West Nile virus (WNV) outbreaks in the Netherlands. Methodology & findingsWe compared a reference scenario to four future Shared Socio-economic Pathway scenarios developed for the Netherlands, which differed in land use, host distribution, mosquito distribution, and temperature. Temperature (between +1.0{degrees}C and +1.7{degrees}C) and mosquito abundance (between +5% and +10%) were predicted to increase during the transmission season across the scenarios. Scenario effects on hosts differed between species. We found that outbreak size and growth rate were expected to increase in all future scenarios for both USUV and WNV. These effects were most pronounced early in the season and in scenarios characterised by a high temperature increase and little concern about environmental change. Changes in outbreak risk differed between locations due to spatial variation in changes in host and vector abundance ConclusionsAcross a range of possible future scenarios, USUV and WNV outbreaks are expected to become larger, grow faster, and last longer. This is mostly driven by increased temperatures, highlighting the importance of climate mitigation measures to reduce disease outbreak risk and impact.

ecology↗

bioRxiv2024

Silent reservoirs are shaping disease emergence: the case of Usutu virus in the Netherlands

Disentangling contributions of different hosts to disease transmission is highly complex, but critical for improving predictions, surveillance, and response. This is particularly challenging in wildlife, with pathogens often infecting multiple species and data collection being difficult. Using the emergence of Usutu virus (USUV) in the Netherlands as a case study, we demonstrate the use of an Approximate Bayesian Computation framework on diverse data sources to uncover drivers of spatio-temporal wildlife disease emergence. We calibrated single- and multi-host mechanistic transmission models to five types of wildlife surveillance and research data, describing molecular and serological evidence of USUV in birds. Although Eurasian blackbirds, the primary target species for surveillance, were most severely affected, our models indicated that USUV could not persist in blackbirds alone. Our framework provided statistical support for additional, unobserved bird species to have contributed to transmission. This population of bird species is characterised by limited infection mortality, a longer lifespan, and likely further dispersal than blackbirds. Immunity in this population appears to have protected blackbirds from further USUV-related population decline. Our results underscore the importance of considering multiple host populations to understand outbreak dynamics. Neglecting the multi-host context of transmission can impact the reliability of predictions and projected impact of interventions.

ecology↗

bioRxiv2024

The future abundance of key bird species for pathogen transmission in the Netherlands

Wild birds serve as reservoirs and vectors for many different pathogens and changes in their distribution and abundance due to environmental change will influence disease risk. We study three species which are highly abundant in north-western Europe and which can transmit a wide range of diseases including avian influenza and West Nile virus: blackbirds, mallards and house sparrows. Using the Netherlands as a case study, we created random forest models for predicting the distribution and abundance of these species, both now and in the future. Climate, land use and vegetative cover were all important predictors of bird abundance. The three species had different spatial distributions, largely related to their preferred habitat and food availability. In the future, mallard and house sparrow populations were predicted to increase, while there was little change for blackbirds. Quantifying the consequences of these abundance changes is complicated as there are many factors to consider, however increased pathogen reservoirs will likely increase disease risk and changes in distribution may affect local outbreak risk. The future abundance maps created in this study, and the methods used to create them, will be useful tools for disease modellers and policymakers to estimate future disease risk and to plan accordingly.

ecology↗