Kawasaki Disease and Pediatric Infectious Diseases During the Coronavirus Disease 2019 Pandemic.

Ae, Ryusuke; Shibata, Yoshihide; Kosami, Koki; Nakamura, Yosikazu; Hamada, Hiromichi

OBJECTIVE To assess the epidemiologic association between Kawasaki disease and common pediatric infectious diseases (PIDs) identified during the coronavirus disease 2019 (COVID-19) pandemic period to confirm whether the infection-triggered theory is a plausible hypothesis for pathogenesis of Kawasaki disease. STUDY DESIGN A retrospective epidemiologic study was conducted using datasets obtained from web-based KD surveillance and surveillance of infectious diseases in Japan. We compared weekly numbers of patients who developed KD and specific PIDs between 2020 and 2017-2019, and evaluated the associations between the percent reduction in the number of patients with these diseases. RESULTS A total of 868 patients developed KD in 2020. During the social distancing period in 2020, the number of patients with KD was approximately 35% lower than in 2017-2019. Days from KD onset until the first hospital visit did not significantly differ among the examined years. Older children with KD decreased greater than infants with KD (<1 year of age), resulting in a significant difference in the proportion of infant patients between 2020 and 2017-2019 (24% vs. 19%; p<0.01). The number of patients with incomplete KD was unchanged from those of previous years. Weekly percent reduction in patient numbers differed between KD and PIDs during 2020, with no strong correlation between both diseases. CONCLUSIONS Our data indicate that parents of patients with Kawasaki disease did not avoid hospital visits during the COVID-19 pandemic period. The findings indicate the possibility that triggering KD might be associated with presently unidentified respiratory pathogen(s) that might be potentially acquired from both within and outside the household.