title: Syndromic surveillance of gastrointestinal illness using pharmacy over-the-counter sales. A retrospective study of waterborne outbreaks in Saskatchewan and Ontario.
abstract: OBJECTIVE
  To ascertain if monitoring over-the-counter (OTC) drug sales could provide a timely syndromic surveillance method of detecting outbreaks of gastrointestinal illness.
  
  
  METHODS
  This study evaluated the potential of a syndromic surveillance system by comparing retrospective pharmacy OTC sales of anti-nauseants and anti-diarrheals to emergency room visits and case numbers from two Canadian outbreaks related to water contamination by Cryptosporidium, and E.coli O157:H7 and Campylobacter.
  
  
  RESULTS
  Local sales trends of weekly aggregate OTC products were comparable to the outbreak epidemic curves. Statistical control tests on the sales data indicated the start of the outbreak periods.
  
  
  CONCLUSIONS
  An automated monitoring tool based on spatial and temporal trend analyses of daily OTC sales would provide supplemental community health information for public health officials that is timelier than currently available laboratory-based surveillance systems.
authors.affiliation: Health Canada, Guelph, Ontario. Victoria_Edge@hc-sc.gc.ca
authors.forename: Victoria L
authors.initials: VL
authors.lastname: Edge
authors.forename: Frank
authors.initials: F
authors.lastname: Pollari
authors.forename: Gillian
authors.initials: G
authors.lastname: Lim
authors.forename: Jeff
authors.initials: J
authors.lastname: Aramini
authors.forename: Paul
authors.initials: P
authors.lastname: Sockett
authors.forename: S Wayne
authors.initials: SW
authors.lastname: Martin
authors.forename: Jeff
authors.initials: J
authors.lastname: Wilson
authors.forename: Andrea
authors.initials: A
authors.lastname: Ellis
mesh_terms: D000930:Antidiarrheals / Q000627:therapeutic use*; D000932:Antiemetics / Q000627:therapeutic use*; D002169:Campylobacter Infections / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D003457:Cryptosporidiosis / Q000453:epidemiology*; D003625:Data Collection / Q000379:methods; D004196:Disease Outbreaks; D004927:Escherichia coli Infections / Q000453:epidemiology*; D019453:Escherichia coli O157 / Q000472:pathogenicity*; D005767:Gastrointestinal Diseases / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D004366:Nonprescription Drugs / Q000627:therapeutic use*; D009864:Ontario / Q000453:epidemiology; D011159:Population Surveillance / Q000379:methods*; D012525:Saskatchewan / Q000453:epidemiology
chemical_list: D000930:Antidiarrheals; D000932:Antiemetics; D004366:Nonprescription Drugs