Volume 91, Issue 2
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



Anaplasmosis is an emerging infectious disease caused by infection with the bacterium . In the eastern United States, is transmitted to hosts through the bite of the blacklegged tick, . We determined the realized reservoir competence of 14 species of common vertebrate hosts for ticks by establishing the probability that each species transmits two important strains of ( human-active, which causes human cases, and variant 1, which does not) to feeding larval ticks. We also sampled questing nymphal ticks from ∼150 sites in a single county over 2 years and sampled over 6 years at one location. White-footed mice () and Eastern chipmunks () were the most competent reservoirs for infection with the human-active strain. Across the county, prevalence in ticks for both strains together was 8.3%; ticks were more than two times as likely to be infected with human-active as variant 1.


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  • Received : 11 Sep 2013
  • Accepted : 17 Apr 2014

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