Evolution of northeastern and midwestern Borrelia burgdorferi, United States

Emerg Infect Dis. 2010 Jun;16(6):911-7. doi: 10.3201/eid1606.090329.


The per capita incidence of human Lyme disease in the northeastern United States is more than twice that in the Midwest. However, the prevalence of Borrelia burgdorferi, the bacterium that causes Lyme disease, in the tick vector is nearly identical in the 2 regions. The disparity in human Lyme disease incidence may result from a disparity in the human invasiveness of the bacteria in the Northeast and Midwest caused by fundamentally different evolutionary histories. B. burgdorferi populations in the Northeast and Midwest are geographically isolated, enabling evolutionary divergence in human invasiveness. However, we found that B. burgdorferi populations in the Northeast and Midwest shared a recent common ancestor, which suggests that substantial evolutionary divergence in human invasiveness has not occurred. We propose that differences in either animal ecology or human behavior are the root cause of the differences in human incidence between the 2 regions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, Bacterial / analysis
  • Antigens, Bacterial / genetics
  • Antigens, Surface / analysis
  • Antigens, Surface / genetics
  • Arachnid Vectors / microbiology
  • Bacterial Outer Membrane Proteins / analysis
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Vaccines / analysis
  • Bacterial Vaccines / genetics
  • Borrelia burgdorferi / genetics*
  • Borrelia burgdorferi / pathogenicity
  • DNA, Bacterial / analysis
  • DNA, Bacterial / genetics
  • Evolution, Molecular*
  • Genetic Variation
  • Humans
  • Lipoproteins / analysis
  • Lipoproteins / genetics
  • Lyme Disease / epidemiology
  • Lyme Disease / microbiology*
  • Midwestern United States / epidemiology
  • New England / epidemiology
  • Phylogeny
  • Prevalence
  • RNA, Ribosomal / analysis
  • RNA, Ribosomal / genetics
  • Recombination, Genetic
  • Ticks / microbiology
  • Virulence


  • Antigens, Bacterial
  • Antigens, Surface
  • Bacterial Outer Membrane Proteins
  • Bacterial Vaccines
  • DNA, Bacterial
  • Lipoproteins
  • OspA protein
  • OspC protein
  • RNA, Ribosomal
  • OspB protein, Borrelia burgdorferi