Epidemiology of Kawasaki disease in Japan in 2021–2022: Results of the 27th nationwide survey
Yosikazu Nakamura, Mayumi Yashiro, Hiroshi Yanagawa
Abstract
BACKGROUND: The number and incidence rate of Kawasaki disease (KD) decreased in 2020. However, the trend thereafter is unknown. METHODS: The 27th nationwide survey of KD was conducted in Japan. The target patients were those with KD in 2021 and 2022. The items that hospitals were asked to report about the individual data for the KD patients were as follows: demographic data, date of the first visit to the hospital because of the disease, classification of the diagnosis, the number of symptoms on the diagnostic guidelines in case of incomplete KD, whether or not it was a recurrent case, family history of KD, whether or not it was a fetal case, cardiac lesions, days of illness at the first visit, first intravenous immunoglobulin therapy, and whether or not the hospital was changed. In addition to these usual data, we obtained information about SARS-CoV-2 infection. RESULTS: Of the 2 years, 21,930 patients (12,649 males and 9281 females, 11,597 in 2021 and 10,333 in 2022). Age and sex distributions were similar to those of the previous year. Seasonal patterns have changed; the disease was most prevalent in August. About 20% of the patients were incomplete cases. The proportion of patients with cardiac sequelae 1 month after onset was 2.3%. Almost all patients were treated with intravenous immunoglobulin, and about 25% of them did not respond to the therapy. Three hundred ninety-three patients (2.0%) were positive for SARS-CoV-2. CONCLUSIONS: Epidemiologic features of KD in Japan in 2021 and 2022 were revealed.