title: Do social media have a place in public health emergency response?
abstract: OBJECTIVE
  To ascertain whether analyses of social media trends for various Twitter responses following a major disaster produce implications for improving the focus on public health resources and messaging to disaster victims.
  
  
  METHODS
  Radian6 and trend analyses were used to analyze 12-hour counts of Twitter data before, during, and after the March 2011 Japanese earthquake and tsunami. Radian6 was used to organize tweets into categories of preparedness, emergency response, and public health.
  
  
  RESULTS
  Radian6 revealed that 49 percent of tweets were either positive or somewhat positive in sentiment about preparedness and only 7 percent were negative or somewhat negative. Trend analyses revealed a rapid onset of tweet activity associated with all keywords followed by mostly fast exponential decline. Analyses indicate that opportunities for improving public health awareness by leveraging social media communications exist for as much as 5 days after a disaster.
  
  
  CONCLUSIONS
  Analyses suggest key times for public health social media communication to promote emergency response.
authors.affiliation: Professor, Department of Health and Kinesiology and Assistant Director, Purdue Homeland Security Institute; Purdue University, West Lafayette, Indiana.
authors.forename: David R
authors.initials: DR
authors.lastname: Black
authors.affiliation: Professor, Computer and Information Technology and Director, Purdue Homeland Security Institute; Purdue University, West Lafayette, Indiana.
authors.forename: J Eric
authors.initials: JE
authors.lastname: Dietz
authors.affiliation: Invasive Disease Epidemiologist, Surveillance and Investigations Division, Indianapolis State Department of Health, Indianapolis, Indiana.
authors.forename: Amanda A
authors.initials: AA
authors.lastname: Stirratt
authors.affiliation: Professor, Department of Mathematics and Statistics, Utah State University, Logan, Utah.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Coster
mesh_terms: D060731:Emergency Responders; D006801:Humans; D033181:Information Dissemination / Q000379:methods*; D020407:Internet; D011634:Public Health; D012189:Retrospective Studies; D061108:Social Media / Q000458:organization & administration*