title: Investigation of an Outbreak of Variant Influenza A(H3N2) Virus Infection Associated With an Agricultural Fair-Ohio, August 2012.
abstract: BACKGROUND
  In 2012, one third of cases in a multistate outbreak of variant influenza A(H3N2) virus ([H3N2]v) infection occurred in Ohio. We conducted an investigation of (H3N2)v cases associated with agricultural Fair A in Ohio.
  
  
  METHODS
  We surveyed Fair A swine exhibitors and their household members. Confirmed cases had influenza-like illness (ILI) and a positive laboratory test for (H3N2)v, and probable cases had ILI. We calculated attack rates. We determined risk factors for infection, using multivariable log-binomial regression.
  
  
  RESULTS
  We identified 20 confirmed and 94 probable cases associated with Fair A. Among 114 cases, the median age was 10 years, there were no hospitalizations or deaths, and 82% had swine exposure. In the exhibitor household cohort of 359 persons (83 households), we identified 6 confirmed cases (2%) and 40 probable cases (11%). An age of <10 years was a significant risk factor (P < .01) for illness. One instance of likely human-to-human transmission was identified.
  
  
  CONCLUSIONS
  In this (H3N2)v outbreak, no evidence of sustained human-to-human (H3N2)v transmission was found. Our risk factor analysis contributed to the development of the recommendation that people at increased risk of influenza-associated complications, including children aged <5 years, avoid swine barns at fairs during the 2012 fair season.
authors.affiliation: Epidemic Intelligence Service Influenza Division.
authors.forename: Adena
authors.initials: A
authors.lastname: Greenbaum
authors.affiliation: Epidemic Intelligence Service Ohio Department of Health, Columbus.
authors.forename: Celia
authors.initials: C
authors.lastname: Quinn
authors.affiliation: Butler County Health Department, Hamilton, Ohio.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Bailer
authors.affiliation: Influenza Division.
authors.forename: Su
authors.initials: S
authors.lastname: Su
authors.affiliation: Epidemic Intelligence Service Influenza Division.
authors.forename: Fiona
authors.initials: F
authors.lastname: Havers
authors.affiliation: Epidemic Intelligence Service US Naval Medical Research Unit No. 6, Lima, Peru.
authors.forename: Lizette O
authors.initials: LO
authors.lastname: Durand
authors.affiliation: Influenza Division.
authors.forename: Victoria
authors.initials: V
authors.lastname: Jiang
authors.affiliation: Ohio Department of Health, Columbus.
authors.forename: Shannon
authors.initials: S
authors.lastname: Page
authors.affiliation: Ohio Department of Health, Columbus.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Budd
authors.affiliation: Influenza Division.
authors.forename: Michael
authors.initials: M
authors.lastname: Shaw
authors.affiliation: Influenza Division.
authors.forename: Matthew
authors.initials: M
authors.lastname: Biggerstaff
authors.affiliation: Ohio Department of Health, Columbus.
authors.forename: Sietske
authors.initials: S
authors.lastname: de Fijter
authors.affiliation: Ohio Department of Health, Columbus.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Smith
authors.affiliation: Influenza Division.
authors.forename: Carrie
authors.initials: C
authors.lastname: Reed
authors.affiliation: Influenza Division.
authors.forename: Scott
authors.initials: S
authors.lastname: Epperson
authors.affiliation: Influenza Division.
authors.forename: Lynnette
authors.initials: L
authors.lastname: Brammer
authors.affiliation: Ohio Department of Health, Columbus.
authors.forename: Dave
authors.initials: D
authors.lastname: Feltz
authors.affiliation: Ohio Department of Health, Columbus.
authors.forename: Kevin
authors.initials: K
authors.lastname: Sohner
authors.affiliation: Ohio Department of Health, Columbus.
authors.forename: Jared
authors.initials: J
authors.lastname: Ford
authors.affiliation: Influenza Division.
authors.forename: Seema
authors.initials: S
authors.lastname: Jain
authors.affiliation: Influenza Division.
authors.forename: Paul
authors.initials: P
authors.lastname: Gargiullo
authors.affiliation: Division of Applied Sciences, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Edward
authors.initials: E
authors.lastname: Weiss
authors.affiliation: Butler County Health Department, Hamilton, Ohio.
authors.forename: Pat
authors.initials: P
authors.lastname: Burg
authors.affiliation: Ohio Department of Health, Columbus.
authors.forename: Mary
authors.initials: M
authors.lastname: DiOrio
authors.affiliation: Ohio Department of Health, Columbus.
authors.forename: Brian
authors.initials: B
authors.lastname: Fowler
authors.affiliation: Influenza Division.
authors.forename: Lyn
authors.initials: L
authors.lastname: Finelli
authors.affiliation: Influenza Division.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Jhung
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000818:Animals; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003441:Crowding; D004196:Disease Outbreaks; D018562:Disease Transmission, Infectious; D005260:Female; D006801:Humans; D007223:Infant; D053122:Influenza A Virus, H3N2 Subtype / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D009820:Ohio / Q000453:epidemiology; D012307:Risk Factors; D013552:Swine; D055815:Young Adult
keywords: influenza; outbreak; variant influenza virus