2022-06-01 07:53:45
Map areas favorable to the presence of ticks
In France, the tick Ixodes ricinus which is present over most of the territory and is the main vector of pathogens responsible for various diseases such as Lyme disease. The activity and life cycle of ticks depend on numerous environmental factors such as climate (oceanic, Mediterranean, continental, etc.), altitude, land use (forests, meadows, urban areas, etc.) or the presence of guests for their meals. An index value from “not favorable” to “very favorable” was assigned to each of these four factors, the presence of hosts being characterized by the density of wild ungulates (data from the French Biodiversity Office). The research team combined knowledge of these factors using multi-criteria decision-making analysis methods that they applied to geographic information systems to create a score map of habitats favorable to Ixodes ricinus.
To validate the approach, they compared the map scores to field data obtained through campaigns to collect ticks at the nymphal stage in mainland France. The map confirms that the most favorable areas for the presence of ticks are in the center, northeast and southwest, while the least favorable habitats are in the Mediterranean and high mountain regions. This map provides information for regions and municipalities and will help to better target prevention messages on tick bites.
A model to predict tick activity based on weather
Tick activity also depends on weather conditions and impacts the risk of transmission of pathogens, including that responsible for Lyme disease. To better understand and describe the activity of ticks, the researchers based themselves on data from a network of 7 observatories spread across mainland France. Since 2014, collection campaigns have been organized monthly in these observatories to estimate the density of ticks but also to measure meteorological (temperature, humidity, etc.) and environmental (altitude, land use, etc.) variables. By bringing together information from 631 collection campaigns, they developed a statistical model making it possible to estimate tick activity depending on location, season and weather variations. This model makes it possible to explain the vast majority of the variations in tick activity observed.
The complementary map and model provide valuable information to identify regions and periods at risk of exposure to ticks in France. The objective is to be able to combine the two to produce tick activity maps based on meteorological data on the scale of mainland France.
1709698331
#tick #weather #maps #mainland #France #Handles
