Predicted northward expansion of the geographic range of the tick vector Amblyomma americanum in North America under future climate conditions

Thumbnail image

Download files

DOI

https://doi.org/10.1289/EHP5668

Language of the publication
English
Date
2019-10-31
Type
Article
Author(s)
  • Sagurova, Irina
  • Ludwig, Antoinette
  • Ogden, Nicholas H.
  • Pelcat, Yann
  • Dueymes, Guillaume
  • Gachon, Philippe
Publisher
EHP Publishing

Abstract

Background: The geographic range of the tick Amblyomma americanum, a vector of diseases of public health significance such as ehrlichiosis, has expanded from the southeast of the United States northward during the 20th century. Recently, populations of this tick have been reported to be present close to the Canadian border in Michigan and New York states, but established populations are not known in Canada. Previous research suggests that changing temperature patterns with climate change may influence tick life cycles and permit northward range expansion of ticks in the northern hemisphere.

Objectives: We aimed to estimate minimal temperature conditions for survival of A. americanum populations at the northern edge of the tick’s range and to investigate the possibility of range expansion of A. americanum into northern U.S. states and southern Canada in the coming decades.

Methods: A simulation model of the tick A. americanum was used, via simulations using climate data from meteorological stations in the United States and Canada, to estimate minimal temperature conditions for survival of A. americanum populations at the northern edge of the tick’s range.

Results: The predicted geographic scope of temperature suitability [≥3,285  annual cumulative degree days (DD) >0°C] included most of the central and eastern U.S. states east of longitude 110°W, which is consistent with current surveillance data for the presence of the tick in this region, as well as parts of southern Quebec and Ontario in Canada. Regional climate model output raises the possibility of northward range expansion into all provinces of Canada from Alberta to Newfoundland and Labrador during the coming decades, with the greatest northward range expansion (up to 1,000km by the year 2100) occurring under the greenhouse gas (GHG) emissions of Representative Concentration Pathway (RCP) 8.5. Predicted northward range expansion was reduced by approximately half under the reduced GHG emissions of RCP4.5.

Discussion: Our results raise the possibility of range expansion of A. americanum into northern U.S. states and southern Canada in the coming decades, and conclude that surveillance for this tick, and the diseases it transmits, would be prudent.

Subject

  • Health,
  • Climate change,
  • Forecasting

Rights

Peer review

Yes

Open access level

Gold

Article

Journal title
Environmental Health Perspectives
Journal volume
127
Journal issue
10

Download(s)

URI

Collection(s)

Communicable diseases

Full item page

Full item page

Page details

Date modified: