title: Evaluation of a syndromic surveillance system using the WSARE algorithm for early detection of an unusual, localized summer outbreak of influenza B: implications for bioterrorism surveillance.
abstract: BACKGROUND
  Syndromic surveillance systems have been developed for early detection of bioterrorist attacks, but few validation studies exist for these systems and their efficacy has been questioned.
  
  
  OBJECTIVE
  To assess the capabilities of a syndromic surveillance system based on community clinics in conjunction with the WSARE algorithm in identifying early signals of a localized unusual influenza outbreak.
  
  
  METHODS
  This retrospective study used data on a documented influenza B outbreak in an elementary school in central Israel. The WSARE algorithm for anomalous pattern detection was applied to individual records of daily patient visits to clinics of one of the four health management organizations in the country.
  
  
  RESULTS
  Two successive significant anomalies were detected in the HMO's data set that could signal the influenza outbreak. If data were available for analysis in real time, the first anomaly could be detected on day 3 of the outbreak, 1 day after the school principal reported the outbreak to the public health authorities.
  
  
  CONCLUSIONS
  Early detection is difficult in this type of fast-developing institutionalized outbreak. However, the information derived from WSARE could help define the outbreak in terms of time, place and the population at risk.
authors.affiliation: Israel Center for Disease Control, Ministry of Health, Tel Hashomer, Israel. zalman.k@icdc.health.gov.il
authors.forename: Zalman
authors.initials: Z
authors.lastname: Kaufman
authors.forename: Weng-Keen
authors.initials: WK
authors.lastname: Wong
authors.forename: Tamar
authors.initials: T
authors.lastname: Peled-Leviatan
authors.forename: Erica
authors.initials: E
authors.lastname: Cohen
authors.forename: Chana
authors.initials: C
authors.lastname: Lavy
authors.forename: Gali
authors.initials: G
authors.lastname: Aharonowitz
authors.forename: Rita
authors.initials: R
authors.lastname: Dichtiar
authors.forename: Michal
authors.initials: M
authors.lastname: Bromberg
authors.forename: Ofra
authors.initials: O
authors.lastname: Havkin
authors.forename: Ehud
authors.initials: E
authors.lastname: Kokia
authors.forename: Manfred S
authors.initials: MS
authors.lastname: Green
mesh_terms: D000293:Adolescent; D000465:Algorithms; D023482:Bioterrorism / Q000517:prevention & control*; D002648:Child; D004196:Disease Outbreaks; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D009981:Influenza B virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis / Q000453:epidemiology*; D007557:Israel; D008297:Male; D012189:Retrospective Studies; D018571:Sentinel Surveillance