To estimate the incidence and describe recent trends of Kawasaki syndrome (KS) in 2 different areas of the United States.
Retrospective analysis of Hawaii and Connecticut State KS hospital discharge records for children younger than 5 years.
In Hawaii, 175 KS hospitalizations for children younger than 5 years were reported during 1994 through 1997; the annual hospitalization rate per 100,000 children was 47.7. The rate for Hawaiian children younger than 1 year (83.2) was greater than that for 1- to 4-year-old children (39.0), and most hospitalizations occurred prior to age 2 years (median age, 17 months). In Connecticut, 171 KS hospitalizations for children younger than 5 years were reported during 1993 through 1996; the annual hospitalization rate per 100,000 children was 18.8, and the median age at hospitalization was 28 months. For both states, most hospitalizations were for boys. Although no clear seasonality was apparent, monthly peaks occurred in some of the years from December through March.
Kawasaki syndrome seems to remain an endemic disease in the United States. A high KS annual hospitalization rate was seen in Hawaii, especially in children younger than 1 year, whereas in Connecticut, the KS rate was more consistent with those previously reported in the continental United States.