title: Validating the Use of Google Trends to Enhance Pertussis Surveillance in California.
abstract: METHODS
  Pertussis has recently re-emerged in the United States. Timely surveillance is vital to estimate the burden of this disease accurately and to guide public health response. However, the surveillance of pertussis is limited by delays in reporting, consolidation and dissemination of data to relevant stakeholders. We fit and assessed a real-time predictive Google model for pertussis in California using weekly incidence data from 2009-2014.
  
  
  CONCLUSIONS
  The linear model was moderately accurate (r = 0.88). Our findings cautiously offer a complementary, real-time signal to enhance pertussis surveillance in California and help to further define the limitations and potential of Google-based epidemic prediction in the rapidly evolving field of digital disease detection.
authors.affiliation: Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, NSW, Australia; Department of Epidemiology & Biostatistics, University of California at San Francisco, California, USA.
authors.forename: Simon
authors.initials: S
authors.lastname: Pollett
authors.affiliation: National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases, The Children's Hospital at Westmead, Sydney, NSW, Australia; Discipline of Paediatrics and Child Health, University of Sydney, NSW, Australia.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Wood
authors.affiliation: Department of Epidemiology & Biostatistics, University of California at San Francisco, California, USA; Department of Medicine, University of California at San Francisco, California, USA.
authors.forename: W John
authors.initials: WJ
authors.lastname: Boscardin
authors.affiliation: Department of Epidemiology & Biostatistics, University of California at San Francisco, California, USA.
authors.forename: Henrik
authors.initials: H
authors.lastname: Bengtsson
authors.affiliation: Department of Epidemiology & Biostatistics, University of California at San Francisco, California, USA.
authors.forename: Sandra
authors.initials: S
authors.lastname: Schwarcz
authors.affiliation: California Department of Public Health, Richmond, California, USA.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Harriman
authors.affiliation: California Department of Public Health, Richmond, California, USA.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Winter
authors.affiliation: Department of Epidemiology & Biostatistics, University of California at San Francisco, California, USA.
authors.forename: George
authors.initials: G
authors.lastname: Rutherford