Temporal and geographical clustering of Kawasaki disease in Japan.

Statistical analysis of the data of Nationwide Surveys of Kawasaki Disease in Japan disclosed that (1) the incidence of the disease clustered temporally. The clustering levels were especially high in the years with high incidence rates. (2) Geographical clustering existed in both epidemic year (1982) and non-epidemic years. Incidence rate were lower in rural area than in urban area. These results support the hypothesis that the etiology of Kawasaki Disease is related to some infectious agents.