title: Right place, wrong species: a 20-year review of rabies virus cross species transmission among terrestrial mammals in the United States.
abstract: BACKGROUND
  In the continental US, four terrestrial mammalian species are reservoirs for seven antigenic rabies virus variants. Cross species transmission (CST) occurs when a rabies virus variant causes disease in non-reservoir species.
  
  
  METHODS
  This study analyzed national surveillance data for rabies in terrestrial mammals. The CST rate was defined as: number of rabid non-reservoir animals/number of rabid reservoir animals. CST rates were analyzed for trend. Clusters of high CST rate counties were evaluated using space-time scanning statistics.
  
  
  RESULTS
  The number of counties reporting a raccoon variant CST rate >1.0 increased from 75 in 1992 to 187 in 2011; counties with skunk variant CST rates >1.0 remained unchanged during the same period. As of 2011, for every rabid raccoon reported within the raccoon variant region, there were 0.73 cases of this variant reported in non-reservoir animals. Skunks were the most common non-reservoir animal reported with the raccoon rabies variant. Domestic animals were the most common non-reservoir animal diagnosed with a skunk rabies virus variant (n = 1,601). Cross species transmission rates increased fastest among domestic animals.
  
  
  CONCLUSIONS
  Cross species transmission of rabies virus variants into non-reservoir animals increases the risk of human exposures and threatens current advances toward rabies control. Cross species transmission in raccoon rabies enzootic regions increased dramatically during the study period. Pet owners should vaccinate their dogs and cats to ensure against CST, particularly in regions with active foci of rabies circulation. Clusters of high CST activity represent areas for further study to better understand interspecies disease transmission dynamics. Each CST event has the potential to result in a rabies virus adapted for sustained transmission in a new species; therefore further understanding of the dynamics of CST may help in early detection or prevention of the emergence of new terrestrial rabies virus variants.
authors.affiliation: Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Wallace
authors.affiliation: National Wildlife Research Center, United States Department of Agriculture, Fort Collins, Colorado, United States of America.
authors.forename: Amy
authors.initials: A
authors.lastname: Gilbert
authors.affiliation: Wildlife Services, United States Department of Agriculture, Concord, New Hampshire, United States of America.
authors.forename: Dennis
authors.initials: D
authors.lastname: Slate
authors.affiliation: Wildlife Services, United States Department of Agriculture, Concord, New Hampshire, United States of America.
authors.forename: Richard
authors.initials: R
authors.lastname: Chipman
authors.affiliation: Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Amber
authors.initials: A
authors.lastname: Singh
authors.affiliation: Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.lastname: Cassie Wedd
authors.affiliation: Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Jesse D
authors.initials: JD
authors.lastname: Blanton
mesh_terms: D000818:Animals; D000829:Animals, Domestic / Q000821:virology; D000835:Animals, Wild / Q000821:virology; D002415:Cats; D004285:Dogs; D012889:Mephitidae / Q000821:virology; D011818:Rabies / Q000635:transmission*; D011820:Rabies virus / Q000472:pathogenicity*; D011821:Raccoons / Q000821:virology; D014481:United States