A Mini-Review of Ixodes Ticks Climate Sensitive Infection Dispersion Risk in the Nordic Region

Abstract

Climate change in the Nordic countries is projected to lead to both wetter and warmer seasons. This, in combination with associated vegetation changes and increased animal migration, increases the potential incidence of tick-borne diseases (TBD) where already occurring, and emergence in new places. At the same time, vegetation and animal management influence tick habitat and transmission risks. In this paper, we review the literature on Ixodes ricinus, the primary vector for TBD. Current and projected distribution changes and associated disease transmission risks are related to climate constraints and climate change, and this risk is discussed in the specific context of reindeer management. Our results indicate that climatic limitations for vectors and hosts, and environmental and societal/institutional conditions will have a significant role in determining the spreading of climate-sensitive infections (CSIs) under a changing climate. Management emerges as an important regulatory “tool” for tick and/or risk for disease transfer. In particular, shrub encroachment, and pasture and animal management, are important. The results underscore the need to take a seasonal view of TBD risks, such as (1) grazing and migratory (host) animal presence, (2) tick (vector) activity, (3) climate and vegetation, and (4) land and animal management, which all have seasonal cycles that may or may not coincide with different consequences of climate change on CSI migration. We conclude that risk management must be coordinated across the regions, and with other land-use management plans related to climate mitigation or food production to understand and address the changes in CSI risks.

Ticks infesting humans and associated pathogens: a cross-sectional study in a 3-year period (2017–2019) in northwest Italy

“…Their occurrence in humans is uncommon [ 39 ]. Almost all pathogens were detected in I. ricinus , the primary vector of TBD, as reported elsewhere [ 3 , 17 ]. Numerous studies have been conducted in northeast Italy, a region that is under continuous surveillance for ticks and associated TBDs [ 5 , 8 , 13 ], whereas surveillance in northwest Italy has been patchy and somewhat limited in terms of defining TBD epidemiology [ 10 , 30 ].…”

Associating Land Cover Changes with Patterns of Incidences of Climate-Sensitive Infections: An Example on Tick-Borne Diseases in the Nordic Area

“…Tick larvae and nymphs mainly feed on small mammals and ground-feeding birds, while the adult ticks prefer to take their blood meal from larger mammals such as ungulates [22]. In northern Europe, the entire life cycle usually takes 2-3 years but can take longer; see [41] for more details on life cycle and hosts. The distribution of ticks and viable tick populations is therefore linked to habitats with climatic conditions suitable for ticks where their hosts reside when foraging [16,18,42,43].…”

“…Ticks depend on their vertebrate hosts for both survival and transport, although a major part of their life cycle is spent away from their vertebrate hosts. Therefore, the local weather conditions and microclimate on the ground influence their activity, development time, survival, and reproductive success [18,41]. Tick vectors are thus likely to be both directly and indirectly affected by the changing climate, and diseases such as tick-borne encephalitis and Lyme borreliosis can be considered climate-sensitive infections (CSIs) [54].…”

Der Einfluss des Klimawandels auf die Ausbreitung von Infektionserkrankungen – am Beispiel der Lyme-Borreliose

“…Zecken werden durchschnittlich 2-3 Jahre alt, können allerdings auch bis zu sechs Jahre überleben (Van Oort et al 2020). Sie durchlaufen in ihrer Entwicklung drei Stadien: Larven, Nymphen und adulte Zecken (Randolph 2004 In den letzten Jahren konnte beobachtet werden, dass Zeckenpopulationen sich innerhalb von Europa nach Norden sowie in größere Höhen ausbreiten (Danielová et al 2010;Jaenson et al 2012;Soleng et al 2018).…”