Epidemiological features of Kawasaki disease in Korea, 2006-2008

Background: The aim of this study was to estimate the incidence and describe the epidemiological characteristics of Kawasaki disease among children in Korea. Methods: Questionnaires for surveying the epidemiology of Kawasaki disease were distributed to a total of 101 hospitals that conduct pediatric residency programs. Then, we retrospectively obtained the data, which covered a three-year period (2006-2008) and analyzed them. Results: During the three-year study period, a total of 9039 cases of Kawasaki disease were reported from 84 hospitals (response rate, 83.2%), comprising 5375 boys and 3664 girls (male : female ratio, 1.47:1). The outbreak rate per 100 000 children < 5 years old was 108.7 in 2006, 118.3 in 2007 and 112.5 in 2008 (average rate, 113.1). The seasonal distribution showed a slightly higher incidence rate in winter and summer. The patients' mean age of onset was 32.6 months, while the proportions of sibling cases and recurrent cases were 0.17% and 2.2%, respectively. Coronary arterial abnormalities were detected during follow up by echocardiogram in 17.5% of all cases including dilatations (16.4%) and aneurysms (2.1%). Conclusions: The average annual incidence rate of Kawasaki disease in Korea has been continuously increasing, and reached 113.1/100 000 children < 5 years old, which is the second highest rate in the world.