Lyme Disease Risks in Europe under Multiple Uncertain Drivers of Change

Abstract

Background:Debates over whether climate change could lead to the amplification of Lyme disease (LD) risk in the future have received much attention. Although recent large-scale disease mapping studies project an overall increase in Lyme disease risk as the climate warms, such conclusions are based on climate-driven models in which other drivers of change, such as land-use/cover and host population distribution, are less considered.Objectives:The main objectives were to project the likely future ecological risk patterns of LD in Europe under different assumptions about future socioeconomic and climate conditions and to explore similarity and uncertainty in the projected risks.Methods:An integrative, spatially explicit modeling study of the ecological risk patterns of LD in Europe was conducted by applying recent advances in process-based modeling of tick-borne diseases, species distribution mapping, and scenarios of land-use/cover change. We drove the model with stakeholder-driven, integrated scenarios of plausible future socioeconomic and climate change [the Shared Socioeconomic Pathway (SSPs) combined with the Representative Concentration Pathways (RCPs)].Results:The model projections suggest that future temperature increases may not always amplify LD risk: Low emissions scenarios (RCP2.6) combined with a sustainability socioeconomic scenario (SSP1) resulted in reduced LD risk. The greatest increase in risk was projected under intermediate (RCP4.5) rather than high-end (RCP8.5) climate change scenarios. Climate and land-use change were projected to have different roles in shaping the future regional dynamics of risk, with climate warming being likely to cause risk expansion in northern Europe and conversion of forest to agriculture being likely to limit risk in southern Europe.Conclusions:Projected regional differences in LD risk resulted from mixed effects of temperature, land use, and host distributions, suggesting region-specific and cross-sectoral foci for LD risk management policy. The integrated model provides an improved explanatory tool for the system mechanisms of LD pathogen transmission and how pathogen transmission could respond to combined socioeconomic and climate changes. https://doi.org/10.1289/EHP4615

Occurrence and Abundance of Dermacentor reticulatus in the Habitats of the Ecological Corridor of the Wieprz River, Eastern Poland

“…The significant effect of temperature on the activity of D. reticulatus was also confirmed in other multi-season studies [33,34]. As in the case of other ixodid ticks [35][36][37], the air temperature exerts an impact on the questing activity of D. reticulatus [13,30], stimulates the rhythms of seasonal tick activity, and induces diapause [38]. This phenomenon is clearly evident in summer in the temperate climate zone when adults are inactive or only a few ticks are active [31,34].…”

Exploratory Space–Time Analyses of Reported Lyme Borreliosis Cases in France, 2016–2019

“…Nevertheless, field studies are good evidence of the geographical expansion of Ixodes ricinus and Borrelia in Europe, especially in northern areas and at a higher altitude, which may be related to global warming, landscape alteration, biodiversity change, or a combination of these, increasing public health concerns [12][13][14][15][16].…”

Could climate trends disrupt the contact rates between Ixodes ricinus (Acari, Ixodidae) and the reservoirs of Borrelia burgdorferi s.l.?

“…Previous modelling approaches on the impact of climate trends on ticks and risk of Lyme borreliosis addressed the changes of the life cycle of the tick under the climate conditions of future scenarios [5,13]. A recent study with similar aims [17] considered Lyme borreliosis risk driven by the presumed abundance of the vector and an estimation of the habitats preferred by vertebrates (without considering particular species), evaluating the expected changes under the conditions of future climate scenarios. That study [17] predicted that an enlarged period of tick development could lead to increased rates of transmission of Borrelia spp.…”

“…However, reports have demonstrated the better performance of jointly modeling both ticks and their vertebrate hosts (or pathogen reservoirs) to capture the probable distribution of health-affecting infectious agents [14]. Few other efforts have exploited process-driven models to capture the life cycle of I. ricinus [15][16][17], and only two of them addressed the potential impact of climate trends on the life cycle of I. ricinus without explicit modeling of the reservoir's range [16], or assuming its presence according to categories of habitat [17].…”