title: Little evidence of human infection with equine influenza during the 2007 epizootic, Queensland, Australia.
abstract: BACKGROUND
  Equine influenza virus (EIV) is considered enzootic in Europe (except Iceland), Asia, North Africa, and North and South America. When EIV outbreaks occur they may severely impact the equine and tourist industries. Australia faced its first EIV outbreak beginning in August of 2007. The outbreak was concentrated in New South Wales and Queensland, with more than 1400 confirmed EIV infections in horses during the first month. Rapid response from the equine industry and the federal government was successful and Australia was declared free from EIV by the end of 2007.
  
  
  OBJECTIVE
  This cross-sectional study was designed to examine associations between exposure to EIV-infected horses and evidence of EIV infection in humans.
  
  
  METHODS
  Employing informed consent, between October 2007 and April 2008, 100 subjects (89 with horse exposures and 11 non-exposed) were enrolled during equine events and at the University of the Sunshine Coast. All subjects provided a blood sample and were asked to complete an online questionnaire including health history, animal exposure and demographic information. Sera samples were tested for the presence of antibodies against two H3N8 EIV strains using microneutralization, hemagglutination inhibition, and enzyme-linked lectin assays.
  
  
  RESULTS
  Evidence for H3N8 infection was sparse, with only 9 study participants having any indication of H3N8 infection and the seroreactivity seen was low and easily explained by cross-reactions against human influenza strains or vaccines.
  
  
  CONCLUSIONS
  These data provide little evidence to support the premise that EIV infections occurred among humans exposed to EIV-infected horses during the 2007 Australian epizootic.
authors.affiliation: School of Health & Sport Sciences, Faculty of Science, Health, Education, & Engineering, University of the Sunshine Coast, Maroochydore, Australia.
authors.forename: Fiona J
authors.initials: FJ
authors.lastname: Burnell
authors.affiliation: School of Health & Sport Sciences, Faculty of Science, Health, Education, & Engineering, University of the Sunshine Coast, Maroochydore, Australia.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Holmes
authors.affiliation: School of Health & Sport Sciences, Faculty of Science, Health, Education, & Engineering, University of the Sunshine Coast, Maroochydore, Australia.
authors.forename: Anne H
authors.initials: AH
authors.lastname: Roiko
authors.affiliation: School of Health & Sport Sciences, Faculty of Science, Health, Education, & Engineering, University of the Sunshine Coast, Maroochydore, Australia.
authors.forename: John B
authors.initials: JB
authors.lastname: Lowe
authors.affiliation: College of Public Health and Health Professions, and Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.
authors.forename: Gary L
authors.initials: GL
authors.lastname: Heil
authors.affiliation: College of Public Health and Health Professions, and Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.
authors.forename: Sarah K
authors.initials: SK
authors.lastname: White
authors.affiliation: College of Public Health and Health Professions, and Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA. Electronic address: gcgray@phhp.ufl.edu.
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Gray
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D001769:Blood / Q000276:immunology; D003430:Cross-Sectional Studies; D006385:Hemagglutination Inhibition Tests; D006734:Horse Diseases / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology; D006736:Horses; D006801:Humans; D053123:Influenza A Virus, H3N8 Subtype / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology; D009500:Neutralization Tests; D009976:Orthomyxoviridae Infections / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D011793:Queensland / Q000453:epidemiology; D016036:Seroepidemiologic Studies; D011795:Surveys and Questionnaires; D055815:Young Adult; D015047:Zoonoses / Q000453:epidemiology* / Q000821:virology
chemical_list: D000914:Antibodies, Viral
keywords: Epidemiology; Influenza A virus, equine; Prospective studies; Seroepidemiologic studies; Zoonoses