title: Contagious comments: what was the online buzz about the 2011 Quebec measles outbreak?
abstract: BACKGROUND
  Although interruption of endemic measles was achieved in the Americas in 2002, Quebec experienced an outbreak in 2011 of 776 reported cases; 80% of these individuals had not been fully vaccinated. We analyzed readers' online responses to Canadian news articles regarding the outbreak to better understand public perceptions of measles and vaccination.
  
  
  METHODS
  We searched Canadian online English and French news sites for articles posted between April 2011 and March 2012 containing the words "measles" and "Quebec". We included articles that i) concerned the outbreak or related vaccination strategies; and ii) generated at least ten comments. Two English and two bilingual researchers coded the unedited comments, categorizing codes to allow themes to emerge.
  
  
  RESULTS
  We analyzed 448 comments from 188 individuals, in response to three French articles and six English articles; 112 individuals expressed positive perceptions of measles vaccination (2.2 comments/person), 38 were negative (4.2 comments/person), 11 had mixed feelings (1.5 comments/person), and 27 expressed no opinion (1.1 comments/person). Vaccine-supportive themes involved the success of vaccination in preventing disease spread, societal responsibility to vaccinate for herd immunity, and refutation of the autism link. Those against measles vaccination felt it was a personal rather than societal choice, and conveyed a distrust of vaccine manufacturers, believing that measles infection is not only safe but safer than vaccination. Commenters with mixed feelings expressed uncertainty of the infection's severity, and varied in support of all vaccines based on perceived risk/benefit ratios.
  
  
  CONCLUSIONS
  The anti-vaccine minority's volume of comments translates to a disproportionately high representation on online boards. Public health messages should address concerns by emphasizing that immunization is always a personal choice in Canada, and that the pharmaceutical industry is strictly controlled. Illustrating the dangers of measles through personal stories, rather than scientific data only, may also serve to strengthen messaging.
authors.affiliation: Public Health Ontario, Toronto, Canada. jennifer.pereira@oahpp.ca
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Pereira
authors.forename: Susan
authors.initials: S
authors.lastname: Quach
authors.forename: Huy Hao
authors.initials: HH
authors.lastname: Dao
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Kwong
authors.forename: Shelley L
authors.initials: SL
authors.lastname: Deeks
authors.forename: Natasha S
authors.initials: NS
authors.lastname: Crowcroft
authors.forename: Sherman D
authors.initials: SD
authors.lastname: Quan
authors.forename: Maryse
authors.initials: M
authors.lastname: Guay
mesh_terms: D004196:Disease Outbreaks; D006801:Humans; D020407:Internet; D008457:Measles / Q000453:epidemiology*; D011792:Quebec / Q000453:epidemiology