Risk maps for range expansion of the Lyme disease vector, Ixodes scapularis, in Canada now and with climate change

Abstract

Background: Lyme disease is the commonest vector-borne zoonosis in the temperate world, and an emerging infectious disease in Canada due to expansion of the geographic range of the tick vector Ixodes scapularis. Studies suggest that climate change will accelerate Lyme disease emergence by enhancing climatic suitability for I. scapularis. Risk maps will help to meet the public health challenge of Lyme disease by allowing targeting of surveillance and intervention activities.

Modeling the Present and Future Geographic Distribution of the Lone Star Tick, Amblyomma americanum (Ixodida: Ixodidae), in the Continental United States

“…This result in directionally consistent with observed and modeled changes in the distribution of I. scapularis, which is most abundant in parts of its range associated with states in Northeast and upper Midwest and is expanding northward into areas of eastern and central Canada. 28,32,37 In our results, the extent of predicted expansion of suitable habitat was greater in the RCP8.5 scenario, which is associated with higher emissions and more extreme warming. Maps for both future ensembles suggested considerable increases in the proportion of suitable habitat in Iowa, Illinois, Indiana, and Ohio.…”

“…[31][32][33] This recognition, and the aforementioned agricultural and public health significance of ticks, underlie a growing interest in tick distribution modeling based on future climate scenarios. [34][35][36][37] Predictions of these models may provide valuable forecasts of changing acarological risk associated with tick-borne diseases that could be used to inform vector monitoring and control efforts and public health campaigns.…”

The Biological Survey of Canada: A Personal History

“…Thus, the distribution of known "endemic" areas for B. burgdorferi infection is limited in Canada but appears to be expanding . Thus, the true geographic extent of reproducing I. scapularis populations in Canada is uncertain (Ogden et al 2008d. However, the number of established populations of I. scapularis is increasing in Canada, the rate of spread is increasing (Ogden et al 2013) and climate change is likely to accelerate this trend (Ogden et al 2008c).…”

Truncated seasonal activity patterns of the western blacklegged tick (Ixodes pacificus) in central and southern California

“…A number of large-scale anthropogenic changes, such as land use and climate change, are contributing to the amplification of emerging infectious zoonotic diseases. For example, the distribution of vector species may shift or expand as a result of climate change, and lead to subsequent shifts in vector-borne disease burden (Bounoua et al, 2013;Ogden et al, 2008b). In the case of pathogens with complex transmission cycles involving multiple hosts and vector life stages, changing host ecology resulting from land use or environmental change may also alter human disease risk through vector abundance (Ogden et al, 2014), infection prevalence with the pathogen (Allan et al, 2003;Patz et al, 2004), or vector activity patterns (Ogden et al, 2008a).…”