Assessment of Pediatric Admissions for Kawasaki Disease or Infectious Disease During the COVID-19 State of Emergency in Japan

Abstract

IMPORTANCEThe development of Kawasaki disease (KD) has been suggested to be associated with droplet-or contact-transmitted infection; however, its triggers and transmission modes remain to be determined. Under an epidemic of SARS-CoV-2, the COVID-19 state of emergency in Japan served as a nationwide social experiment to investigate the impact of quarantine or isolation on the incidence of KD.OBJECTIVE To assess the role of droplet or contact transmission in the etiopathogenesis of KD. DESIGN, SETTING, AND PARTICIPANTSThis multicenter, longitudinal, cross-sectional study was conducted from 2015 to 2020 at Fukuoka Children's Hospital and 5 adjacent general hospitals. The number of admissions for KD and infectious diseases were analyzed. Participants were pediatric patients admitted to the participating hospitals for KD or infectious diseases. EXPOSURES Quarantine and isolation owing to the COVID-19 state of emergency. MAIN OUTCOMES AND MEASURES The primary end points were the ratios of patients with KD to patients with respiratory tract or gastrointestinal infections admitted from April to May in 2015 to 2019 and 2020. A Poisson regression model was used to analyze them. RESULTSThe study participants included 1649 patients with KD (median [interquartile range] age, 25 months; 901 boys [54.6%]) and 15 586 patients with infectious disease (data on age and sex were not available for these patients). The number of admissions for KD showed no significant change between April and May in 2015 to 2019 vs the same months in 2020 (mean [SD], 24.8 [5.6] vs

Multi‐inflammatory syndrome and Kawasaki disease in children during the COVID‐19 pandemic: A nationwide register‐based study and time series analysis

“…Thus, the reduced transmission of microbes other than SARS‐CoV‐2 may explain the observed decreased incidence of Kawasaki disease in the present study. Our finding was in line with a study from six hospitals in Japan, which showed a possible 27% reduction in Kawasaki disease, with an incidence rate ratio of 0.73 (95% CI: 0.48‐1.10) during the COVID‐19 pandemic 21 . The aetiopathogenesis of Kawasaki disease has been extensively studied but is not fully understood.…”

Global epidemiology of vasculitis

“…The existence of these sub-phenotypes suggests that Kawasaki disease might be triggered by diverse agents that each yield slight variations in clinical presentation 98 . A surprising observation from the past year is the large decrease in the incidence of Kawasaki disease in Japan and the USA during the SARS-CoV-2 pandemic, which supports the hypothesis that Kawasaki disease is triggered by inhaled aerosols that can be blocked or reduced by the use of facial masking 99 , 100 . The possibility of long-range transport of aerosols linked to fluctuations in Kawasaki disease incidence has been studied in both Northern and Southern Hemispheres 93 , 101 , 102 .…”

Number of Kawasaki Disease Admissions Is Associated with Number of Domestic COVID-19 and Severe Enterovirus Case Numbers in Taiwan

“…In other countries where COVID-19 infection rates are similarly low, such as Japan, South Korea, and Finland (cumulative COVID-19 incidence rates of 1363.841, 762.093, and 3231.09 per 100,000 people, respectively) [ 6 ], KD incidence rates declined following the implementation of public health measures in 2020. In Japan, where a state of emergency was declared from 7 April–25 May 2020, and school closures were enacted between 2 March–31 May 2020, incidence rates of KD began to decline beginning in March in 11 hospitals in the Yamanashi prefecture [ 14 ], in April in 18 hospitals in the Kobe area [ 15 ], and in June in six hospitals in Fukuoka [ 16 ]. In both Finland and South Korea, KD incidence rates declined after the implementation of school closures.…”