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Detecting the Lyme Disease Spirochete, Borrelia Burgdorferi, in Ticks Using Nested PCR
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Evolution of northeastern and midwestern Borrelia burgdorferi, United States

Dustin Brisson1, Mary F Vandermause, Jennifer K Meece

  • 1Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6018, USA. dbrisson@sas.upenn.edu

Emerging Infectious Diseases
|May 29, 2010
PubMed

Insights

Lyme disease (Borrelia burgdorferi) affects the Northeast US more than the Midwest. Differences in bacterial evolution don't explain this, suggesting animal or human behavior drives the disparity.

Area of Science:

  • Epidemiology
  • Microbiology
  • Evolutionary Biology

Background:

  • Human Lyme disease incidence is significantly higher in the northeastern United States compared to the Midwest.
  • The prevalence of Borrelia burgdorferi, the causative agent of Lyme disease, within tick vectors is similar across both regions.
  • This suggests factors beyond tick infection rates influence regional disease incidence.

Purpose of the Study:

  • To investigate the evolutionary history of Borrelia burgdorferi populations in the Northeast and Midwest.
  • To determine if evolutionary divergence in bacterial invasiveness explains the disparity in human Lyme disease incidence between these regions.

Main Methods:

  • Phylogenetic analysis of Borrelia burgdorferi populations.
  • Comparison of bacterial genetic divergence and geographic isolation.

Main Results:

  • Borrelia burgdorferi populations in the Northeast and Midwest share a recent common ancestor.
  • No substantial evolutionary divergence in human invasiveness was detected between the two regions.
  • This finding challenges the hypothesis that differing bacterial evolutionary histories drive regional Lyme disease incidence.

Conclusions:

  • The disparity in human Lyme disease incidence between the Northeast and Midwest is unlikely due to divergent evolutionary paths of Borrelia burgdorferi.
  • Alternative explanations, such as variations in animal host ecology or human behavior, are proposed as the primary drivers.
  • Further research into ecological and behavioral factors is warranted to understand regional Lyme disease prevalence.

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