Nested Species Distribution Models of Chlamydiales in Ixodes ricinus (Tick) Hosts in Switzerland

Abstract

The tick Ixodes ricinus is the vector of various pathogens, including Chlamydiales bacteria, potentially causing respiratory infections. In this study, we modelled the spatial distribution of I. ricinus and associated Chlamydiales over Switzerland from 2009 to 2019. We used a total of 2293 ticks and 186 Chlamydiales occurrences provided by a Swiss Army field campaign, a collaborative smartphone application and a prospective campaign. For each tick location, we retrieved from Swiss federal datasets the environmental factors reflecting the topography, climate and land cover. We then used the Maxent modelling technique to estimate the suitability for I. ricinus and to subsequently build the nested niche of Chlamydiales bacteria. Results indicate that I. ricinus high habitat suitability is determined by higher temperature and vegetation index (NDVI) values, lower temperature during driest months and a higher percentage of artificial and forests areas. The performance of the model was increased when extracting the environmental variables for a 100 m-radius buffer around the sampling points and when considering the climatic conditions of the two years previous to sampling date. For Chlamydiales bacteria, the suitability was favoured by lower percentage of artificial surfaces, driest conditions, high precipitation during coldest months and short distances to wetlands. From 2009 to 2018, we observed an extension of tick and Chlamydiales suitable areas, associated with a shift towards higher altitude. The importance to consider spatio-temporal variations of the environmental conditions for obtaining better prediction was also demonstrated. Importance Ixodes ricinus is the vector of pathogens, including the agent of Lyme disease, the tick borne encephalitis virus and the less known Chlamydiales bacteria at the origin of some respiratory infections. In this study, we identified the environmental factors influencing the presence of I. ricinus and Chlamydiales in Switzerland and generated maps of their distribution from 2009 to 2018. We found an important expansion of suitable areas for both the tick and the bacteria during the last decade. Results provided also the environmental factors that determine the presence of Chlamydiales within ticks. Distribution maps as generated here are expected to bring valuable informations for decision-makers to control tick-borne diseases in Switzerland and establish prevention campaigns. The methodological framework presented could be used to predict the distribution and spread of other host-pathogen couples, to identify environmental factors driving their distribution and to develop control or prevention strategies accordingly.

Current Risk of Dirofilariosis Transmission in the Iberian Peninsula (Spain and Portugal) and the Balearic Islands (Spain) and Its Future Projection under Climate Change Scenarios

“…In this methodological field of ENMs, we are hardly aware of any studies in relation to parasitic diseases and their vectors [43][44][45][46][47][48][49][50][51][52][53][54][55][56] and none in relation to dirofilariosis. Most of the studies that analyze the risk of infection by Dirofilaria spp.…”

Revealing large‐scale parasite ranges: An integrated spatiotemporal database and multisource analysis of the winter tick

“…As blood‐feeding ectoparasites capable of transmitting pathogenic agents to humans, ticks have been a strong focus in parasite‐climate research over the past decade, often with the aim of obtaining and improving predictions of their ranges under expected, long‐term climate warming regimes (Dantas‐Torres, 2015; Gasmi et al, 2018; Sonenshine, 2018). The increasing body of evidence pertaining to climate‐mediated range changes in ticks is reflected in the numerous studies modeling and mapping the distribution of the blacklegged tick, Ixodes scapularis , in North America (e.g., Glass et al, 2021; Leighton et al, 2012; Lieske & Lloyd, 2018; Slatculescu et al, 2020) and the castor bean or sheep tick, Ixodes ricinus , in Europe (e.g., Boehnke et al, 2015; Fernández‐Ruiz & Estrada‐Peña, 2020; Rochat et al, 2020; Zanet et al, 2020). Given the role of these species as potential vectors of several disease‐causing agents (Dantas‐Torres et al, 2012; Sonenshine & Mather, 1994), understanding when and where such species occur and their potential to interact with humans has clear implications for public health (Eisen & Paddock, 2021).…”

Multiscale Very High Resolution Topographic Models in Alpine Ecology: Pros and Cons of Airborne LiDAR and Drone-Based Stereo-Photogrammetry Technologies

“…To investigate the ecological relevance of DEM-derived variables from LiDAR and PHOTO at various spatial resolutions, we performed SDMs at each site following the methods of [56]. As we had presence-only data of A. alpina across the sites, we used the machine learning method of MaxEnt [57] through the R package, maxnet [58], to estimate the probability distribution n of the plants across the sites based on incomplete species presence-only data and environmental predictor variables [59,60].…”