title: Live Animal Markets in Minnesota: A Potential Source for Emergence of Novel Influenza A Viruses and Interspecies Transmission.
abstract: BACKGROUND
  Live animal markets have been implicated in transmission of influenza A viruses (IAVs) from animals to people. We sought to characterize IAVs at 2 live animal markets in Minnesota to assess potential routes of occupational exposure and risk for interspecies transmission.
  
  
  METHODS
  We implemented surveillance for IAVs among employees, swine, and environment (air and surfaces) during a 12-week period (October 2012-January 2013) at 2 markets epidemiologically associated with persons with swine-origin IAV (variant) infections. Real-time reverse transcription polymerase chain reaction (rRT-PCR), viral culture, and whole-genome sequencing were performed on respiratory and environmental specimens, and serology on sera from employees at beginning and end of surveillance.
  
  
  RESULTS
  Nasal swabs from 11 of 17 (65%) employees tested positive for IAVs by rRT-PCR; 7 employees tested positive on multiple occasions and 1 employee reported influenza-like illness. Eleven of 15 (73%) employees had baseline hemagglutination inhibition antibody titers ≥40 to swine-origin IAVs, but only 1 demonstrated a 4-fold titer increase to both swine-origin and pandemic A/Mexico/4108/2009 IAVs. IAVs were isolated from swine (72/84), air (30/45), and pen railings (5/21). Whole-genome sequencing of 122 IAVs isolated from swine and environmental specimens revealed multiple strains and subtype codetections. Multiple gene segment exchanges among and within subtypes were observed, resulting in new genetic constellations and reassortant viruses. Genetic sequence similarities of 99%-100% among IAVs of 1 market customer and swine indicated interspecies transmission.
  
  
  CONCLUSIONS
  At markets where swine and persons are in close contact, swine-origin IAVs are prevalent and potentially provide conditions for novel IAV emergence.
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Choi
authors.affiliation: University of Minnesota College of Veterinary Medicine, Minnesota Center of Excellence for Influenza Research and Surveillance.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Torremorell
authors.affiliation: University of Minnesota College of Veterinary Medicine, Minnesota Center of Excellence for Influenza Research and Surveillance.
authors.forename: Jeff B
authors.initials: JB
authors.lastname: Bender
authors.affiliation: Minnesota Department of Health, St Paul.
authors.forename: Kirk
authors.initials: K
authors.lastname: Smith
authors.affiliation: Minnesota Department of Health, St Paul.
authors.forename: David
authors.initials: D
authors.lastname: Boxrud
authors.affiliation: University of Minnesota College of Veterinary Medicine, Minnesota Center of Excellence for Influenza Research and Surveillance.
authors.forename: Jon R
authors.initials: JR
authors.lastname: Ertl
authors.affiliation: University of Minnesota College of Veterinary Medicine, Minnesota Center of Excellence for Influenza Research and Surveillance.
authors.forename: My
authors.initials: M
authors.lastname: Yang
authors.affiliation: University of Minnesota College of Veterinary Medicine, Minnesota Center of Excellence for Influenza Research and Surveillance.
authors.forename: Kamol
authors.initials: K
authors.lastname: Suwannakarn
authors.affiliation: Minnesota Department of Health, St Paul.
authors.forename: Duachi
authors.initials: D
authors.lastname: Her
authors.affiliation: Minnesota Department of Health, St Paul.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Nguyen
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Uyeki
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Min
authors.initials: M
authors.lastname: Levine
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Lindstrom
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Katz
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Michael
authors.initials: M
authors.lastname: Jhung
authors.affiliation: Minnesota Department of Health, St Paul.
authors.forename: Sara
authors.initials: S
authors.lastname: Vetter
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Karen K
authors.initials: KK
authors.lastname: Wong
authors.affiliation: University of Minnesota College of Veterinary Medicine, Minnesota Center of Excellence for Influenza Research and Surveillance.
authors.forename: Srinand
authors.initials: S
authors.lastname: Sreevatsan
authors.affiliation: Minnesota Department of Health, St Paul.
authors.forename: Ruth
authors.initials: R
authors.lastname: Lynfield
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D004783:Environmental Microbiology; D062665:Epidemiological Monitoring; D006801:Humans; D009980:Influenza A virus / Q000302:isolation & purification*; D040541:Marketing; D008910:Minnesota; D016273:Occupational Exposure; D009976:Orthomyxoviridae Infections / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D011446:Prospective Studies; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013552:Swine; D013553:Swine Diseases / Q000635:transmission* / Q000821:virology; D014776:Virus Cultivation; D015047:Zoonoses / Q000635:transmission* / Q000821:virology
chemical_list: D000914:Antibodies, Viral
keywords: human; influenza; live animal markets; swine