title: Monitoring sheep and Culicoides midges in Montana for evidence of Bunyamwera serogroup virus infection.
abstract: BACKGROUND
  A serological and entomological investigation was performed to monitor for potential Bunyamwera (BUN) serogroup virus activity in Montana.
  
  
  RESULTS
  To facilitate the serological investigation, sera were collected from 104 sheep in 2013 and 2014 and assayed by plaque reduction neutralization test using all six BUN serogroup viruses known to occur in the United States: Cache Valley virus (CVV), Lokern virus (LOKV), Main Drain virus (MDV), Northway virus, Potosi virus and Tensaw virus. BUN serogroup virus-specific antibodies were detected in 41 (39%) sheep. Of these, three were seropositive for MDV, one was seropositive for CVV, one was seropositive for LOKV and 36 had antibodies to an undetermined BUN serogroup virus. Additionally, 30,606 Culicoides sonorensis were collected in 2013 using Centers for Disease Control and Prevention (CDC) light traps and assayed for cytopathic virus by virus isolation in African Green Monkey kidney (Vero) cells. All midges were negative. Almost one-third of the midges were further tested by reverse transcription-polymerase chain reaction using BUN serogroup virus-reactive primers and all were negative.
  
  
  CONCLUSIONS
  We provide evidence of BUN serogroup virus infection in sheep but not C. sonorensis in Montana in 2013-2014. This study also provides the first evidence of CVV, MDV and LOKV activity in Montana.
authors.affiliation: Department of Animal and Range Sciences , Montana State University , Bozeman, Montana , USA.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Johnson
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine , College of Veterinary Medicine, Iowa State University , Ames, Iowa , USA.
authors.forename: Charlie S
authors.initials: CS
authors.lastname: Bahnson
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine , College of Veterinary Medicine, Iowa State University , Ames, Iowa , USA.
authors.forename: Patricia
authors.initials: P
authors.lastname: Ishii
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine , College of Veterinary Medicine, Iowa State University , Ames, Iowa , USA.
authors.forename: Zachary N
authors.initials: ZN
authors.lastname: Cochrane
authors.affiliation: Department of Natural Science , Carroll College , Helena, Montana , USA.
authors.forename: D Grant
authors.initials: DG
authors.lastname: Hokit
authors.affiliation: Department of Veterinary and Diagnostic Production Animal Medicine , College of Veterinary Medicine, Iowa State University , Ames, Iowa , USA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Plummer
authors.affiliation: Department of Entomology , College of Agriculture and Life Sciences, Iowa State University , Ames, Iowa , USA.
authors.forename: Lyric C
authors.initials: LC
authors.lastname: Bartholomay
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine , College of Veterinary Medicine, Iowa State University , Ames, Iowa , USA.
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: Blitvich
keywords: Bunyamwera serogroup; Cache Valley virus; Culicoides; Orthobunyavirus; Sheep; Surveillance