title: Temporal and geographical clustering of Kawasaki disease in Japan: 2007-2012.
abstract: BACKGROUND
  Since 1987, no study has reported the municipal-level geographical clustering of Kawasaki disease (KD) in Japan. Therefore, the aim of the present study was to identify the temporal and municipal-level geographical clustering of KD.
  
  
  METHODS
  The annual incidence rates of KD for each municipality were calculated using nationwide data from 73 758 patients with KD (2007-2012). To determine whether temporal and municipal-level clustering existed, we calculated the correlations of the annual incidence rates for each municipality during the study years, and compared these rates with those of the adjacent municipalities. Spatial scanning analysis was used to identify the geographical clusters for each year, and the incidence rates in those clusters were compared with the rates in the surrounding region.
  
  
  RESULTS
  The annual national incidence rate of KD, adjusted for the prefecture-specific response rate, was 322.45 patients per 100 000 children aged 0-4 years. The correlation between the annual incidence rates during 2 consecutive years was significantly positive (coefficients, 0.149-0.428). On spatial scanning analysis, the most likely clusters were in the Tokyo metropolitan area during 2007-2010 and 2012, and in Kumamoto prefecture during 2011.
  
  
  CONCLUSIONS
  Kawasaki disease exhibits temporal and municipal-level clustering.
authors.affiliation: Division of Public Health Center for Community Medicine Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Sano
authors.affiliation: Division of Public Health Center for Community Medicine Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Nobuko
authors.initials: N
authors.lastname: Makino
authors.affiliation: Division of Public Health Center for Community Medicine Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Aoyama
authors.affiliation: Division of Public Health Center for Community Medicine Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Ae
authors.affiliation: Division of Public Health Center for Community Medicine Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Kojo
authors.affiliation: Division of Public Health Center for Community Medicine Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Kotani
authors.affiliation: Division of Public Health Center for Community Medicine Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Yosikazu
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Division of Public Health Center for Community Medicine Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yanagawa
mesh_terms: D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D008297:Male; D009080:Mucocutaneous Lymph Node Syndrome / Q000453:epidemiology*; D012189:Retrospective Studies
keywords: Japan; epidemiology; incidence study; mucocutaneous lymph node syndrome; space-time clustering