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Emergence of a Novel Human Ehrlichia-muris Like Organism in North America – Wisconsin and Minnesota
The New England Journal of Medicine (2011)
  • Bobbi S. Pritt, Mayo Clinic
  • Lynne M. Sloan, Mayo Clinic
  • Diep K. Hoang-Johnson
  • Ulrike G. Munderloh, University of Minnesota
  • Susan M. Paskewitz, University of Wisconsin - Madison
  • Kristina M. McElroy
  • Jevon D. McFadden
  • Matthew J. Binnicker, Mayo Clinic
  • David F. Neitzel, University of Minnesota
  • Gongping Liu, University of Minnesota
  • William L. Nicholson
  • Curtis M. Nelson, University of Minnesota
  • Joni J. Franson
  • Scott A. Martin
  • Scott A. Cunningham, Mayo Clinic
  • Christopher R. Steward
  • Kay Bogumill
  • Mary E. Bjorgaard
  • Jeffrey P. Davis
  • Jennifer H. McQuiston
  • David M. Warshauer
  • Mark P. Wilhelm, Mayo Clinic
  • Robin Patel, Mayo Clinic
  • Vipul A. Trivedi
  • Marina Eremeeva, Georgia Southern University

Background: Ehrlichiosis is a clinically important, emerging zoonosis. Only Ehrlichia chaffeensis and E. ewingii have been thought to cause ehrlichiosis in humans in the United States. Patients with suspected ehrlichiosis routinely undergo testing to ensure proper diagnosis and to ascertain the cause.

Methods: We used molecular methods, culturing, and serologic testing to diagnose and ascertain the cause of cases of ehrlichiosis.

Results: On testing, four cases of ehrlichiosis in Minnesota or Wisconsin were found not to be from E. chaffeensis or E. ewingii and instead to be caused by a newly discovered ehrlichia species.

All patients had fever, malaise, headache, and lymphopenia; three had thrombocytopenia; and two had elevated liver-enzyme levels. All recovered after receiving doxycycline treatment. At least 17 of 697 Ixodes scapularis ticks collected in Minnesota or Wisconsin were positive for the same ehrlichia species on polymerase-chain-reaction testing. Genetic analyses revealed that this new ehrlichia species is closely related to E. muris.

Conclusions: We report a new ehrlichia species in Minnesota and Wisconsin and provide supportive clinical, epidemiologic, culture, DNA-sequence, and vector data. Physicians need to be aware of this newly discovered close relative of E. muris to ensure appropriate testing, treatment, and regional surveillance. (Funded by the National Institutes of Health and the Centers for Disease Control and Prevention).

  • Ehrlichiosis,
  • Zoonosis,
  • Minnesota,
  • Wisconsin
Publication Date
January 1, 2011
Publisher Statement
This is an Accepted Author Manuscript obtained from PMC. The publisher's final edited version of this article is available at The New England Journal of Medicine.
Citation Information
Bobbi S. Pritt, Lynne M. Sloan, Diep K. Hoang-Johnson, Ulrike G. Munderloh, Susan M. Paskewitz, Kristina M. McElroy, Jevon D. McFadden, Matthew J. Binnicker, David F. Neitzel, Gongping Liu, William L. Nicholson, Curtis M. Nelson, Joni J. Franson, Scott A. Martin, Scott A. Cunningham, Christopher R. Steward, Kay Bogumill, Mary E. Bjorgaard, Jeffrey P. Davis, Jennifer H. McQuiston, David M. Warshauer, Mark P. Wilhelm, Robin Patel, Vipul A. Trivedi, and Marina E. Eremeeva. "Emergence of a Novel Human Ehrlichia-muris Like Organism in North America – Wisconsin and Minnesota" The New England Journal of Medicine 365.5 (2011): 422-429.
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