Epidemiology of Kawasaki Disease

Abstract

Kawasaki disease is an acute systemic vasculitis involving mainly the small and medial arteries. It usually presents with acute inflammatory symptoms and signs in infancy and early childhood, and results in coronary arterial lesions in 20% and about 5% of patients during the acute and convalescent stages, respectively. Those late cardiovascular sequelae of coronary arterial lesions may lead to myocardial ischemia, angina pectoris, myocardial infarction, and even early cardiac death in adulthood. Although thousands of studies and reports have been published since 1961, when this particular disease was first reported by Tomisaku Kawasaki, the etiology is still unknown. Many reports drew attention to the racial/ethnic difference and genetic susceptibility of this disease, 1 and epidemiological surveys have been conducted and reported in many countries. 2e5 Lue et al 6 report the epidemiological features of Kawasaki disease in this issue. They concluded that, since Kawasaki disease was first reported in Taiwan in 1976, it increased to a total of 14,399 patients by 2007, with the highest patient number of 1018 in 2001, and the highest incidence of 66.24 among 100,000 children aged <5 years in 2006. The male-to-female ratio ranges from 1.5 to 1.7. During the past 30 years, 14 cases have died with the fatality rate decreasing from 0.4% to 0.03%. The annual increment rate was lower than that in Japan (2.41 vs. 4.17). There has been no significant outbreak in Taiwan. 6 The epidemiological features showed a small but not significant difference when compared to the studies using the National Health Insurance database 2003e2006 5 and 2008e2010. 2 Chang et al 7 studied the urban versus rural environmental difference by using the National Health Insurance database and did not find any significant difference in different geographical locations in Taiwan. From epidemiological studies on Kawasaki disease, we findthatTaiwanhasthethirdhighestprevalenceofKawasaki disease worldwide. Because the etiology is still unknown, further studies on the possible infectious or genetic origins, best treatment, and long-term sequelae are mandatory. The increased incidence of incomplete Kawasaki disease has also been reported worldwide, so early suspicion and evaluation of young infants with prolonged fever should be performed to avoid the delay of diagnosis and to provide proper timely treatment of Kawasaki disease.