Climate change and habitat fragmentation drive the occurrence of Borrelia burgdorferi, the agent of Lyme disease, at the northeastern limit of its distribution

Abstract

Lyme borreliosis is rapidly emerging in Canada, and climate change is likely a key driver of the northern spread of the disease in North America. We used field and modeling approaches to predict the risk of occurrence of Borrelia burgdorferi, the bacteria causing Lyme disease in North America. We combined climatic and landscape variables to model the current and future (2050) potential distribution of the black-legged tick and the white-footed mouse at the northeastern range limit of Lyme disease and estimated a risk index for B. burgdorferi from these distributions. The risk index was mostly constrained by the distribution of the white-footed mouse, driven by winter climatic conditions. The next factor contributing to the risk index was the distribution of the black-legged tick, estimated from the temperature. Landscape variables such as forest habitat and connectivity contributed little to the risk index. We predict a further northern expansion of B. burgdorferi of approximately 250–500 km by 2050 – a rate of 3.5–11 km per year – and identify areas of rapid rise in the risk of occurrence of B. burgdorferi. Our results will improve understanding of the spread of Lyme disease and inform management strategies at the most northern limit of its distribution.

Linkages of Weather and Climate WithIxodes scapularisandIxodes pacificus(Acari: Ixodidae), Enzootic Transmission ofBorrelia burgdorferi, and Lyme Disease in North America

“…However, such interannual variations in tick abundance also are strongly impacted by changes in abundance of key hosts for immatures (rodents) and adults (deer), which may or may not be related to weather conditions (Ostfeld et al 2006, Simon et al 2014). Contributing to our uncertainty in the effects of weather on interannual variation in tick abundance is limited data on: 1) mortality rates of each tick life stage related to weather effects at different times of the year; and 2) the shape and magnitude of the relationships between abundance of key hosts and abundance of host-seeking nymphs, particularly extended over multiple years.…”

Homologous Recombination and Xylella fastidiosa Host–Pathogen Associations in South America

“…Long-distance dispersal mediated by anthropogenic activities, land use changes, abiotic or biotic modifications affecting host biology or ecology, pathogen evolution, as well as other factors such as climate alterations all have been shown to drive emergence of animal, plant, and human diseases (Daszak et al 2000;Hacker and Carniel 2001;Hufbauer et al 2012;Murray and Daszak 2013).Within this context, however, the emergence of diseases caused by related pathogens is usually associated with a limited number of drivers. For example, flu pandemics are linked to virus reassortments (Garten et al 2009) and bird migrations (Verhagen et al 2015), while land use and climate change affect the occurrence of Lyme disease in North America (Simon et al 2014). Therefore, broadly observed patterns serve as starting points when evaluating factors associated with emerging diseases caused by related pathogens.…”

Effects of parasite and historic driven selection on the diversity and structure of a MHC-II gene in a small mammal species (Peromyscus leucopus) undergoing range expansion

“…However, field observations over the last decade, recording the presence of white footed mice at higher latitude year after year (RoyDufresne et al 2013), tend to prove that global warming remain the major factor driving the expansion of the species. This warrants further research, as the rate and pattern of emergence of Lyme disease in Southern Quebec is dependent on the expansion rate of P. leucopus in the region (Simon et al 2014). …”