Climate change influences on the potential geographic distribution of the disease vector tick Ixodes ricinus

Abstract

BackgroundIxodes ricinus is a species of hard tick that transmits several important diseases in Europe and North Africa, including Lyme borreliosis and tick-borne encephalitis. Climate change is affecting the geographic distributions and abundances of arthropod vectors, which in turn influence the geographic distribution and epidemiology of associated vector-borne diseases. To date, few studies have investigated effects of climate change on the spatial distribution of I. ricinus at continental extents. Here, we assessed the potential distribution of I. ricinus under current and future climate conditions to understand how climate change will influence the geographic distribution of this important tick vector in coming decades.MethodWe used ecological niche modeling to estimate the geographic distribution of I. ricinus with respect to current climate, and then assessed its future potential distribution under different climate change scenarios. This approach integrates occurrence records of I. ricinus with six relevant environmental variables over a continental extent that includes Europe, North Africa, and the Middle East. Future projections were based on climate data from 17 general circulation models (GCMs) under 2 representative concentration pathway emissions scenarios (RCPs), for the years 2050 and 2070.ResultThe present and future potential distributions of I. ricinus showed broad overlap across most of western and central Europe, and in more narrow zones in eastern and northern Europe, and North Africa. Potential expansions were observed in northern and eastern Europe. These results indicate that I. ricinus populations could emerge in areas in which they are currently lacking, posing increased risks to human health in those areas. However, the future of I. ricinus ticks in some important regions such the Mediterranean was unclear owing to high uncertainty in model predictions.

Impact of recent and future climate change on vector‐borne diseases

“…[150][151][152] Future scenarios indicate a potential further expansion of I. ricinus in northern and eastern Europe. 153 The number of Lyme disease cases in Europe has steadily increased from about 3000 in the early 1990s to 35,000 in the late 2000s. 154 In the United States, 155 The number of Lyme disease cases has more than doubled in the United States since the 1990s, and Lyme disease is now believed to affect about 300,000 Americans annually.…”

High tick abundance and diversity of tick-borne pathogens in a Finnish city

“…Both the abundance of ticks and the numbers of diagnosed tick-borne diseases have increased in many European countries in recent decades (e.g., Jaenson et al 2012;Sajanti et al 2017). Not all of the reasons for these increases have been explored, but a substantial role for the changing climate has commonly been emphasized (e.g., Jaenson et al 2012;Medlock et al 2013; Estrada-Peña and de la Fuente 2014; Jore et al 2014;Medlock and Leach 2015;Alkishe et al 2017). Warmer winters, prolonged growing season and other climatic changes are suggested to have direct effects on tick and pathogen performance and indirect effects on tick dynamics via density and range shifts in host animal populations.…”

Critical diapause portion for oscillations: Parametric trigonometric functions and their applications for Hopf bifurcation analyses

“…These diseases are transmitted through the bites of infected ticks, with I ricinus and I persulcatus prevailing in Asia and Europe being the most abundant and medically significant tick species responsible for the majority of TBDs, TBE, and Lyme Borrelli . Because of climate change and urban sprawl, ticks are increasing drawing close to human . So understanding tick population dynamics is becoming more and more relevant for the control of a wide range of tick‐borne diseases …”

“…18 Because of climate change and urban sprawl, ticks are increasing drawing close to human. [19][20][21] So understanding tick population dynamics is becoming more and more relevant for the control of a wide range of tick-borne diseases. [22][23][24] An important factor that has significant impact for the tick population dynamics is the diapause, a physiological phenomenon defined as a state of suspended development activity, which ensures the survival of ticks.…”