Kawasaki disease incidence curbed by COVID-19 lockdown behaviors
Cases of Kawasaki disease dropped 28% during the COVID-19 pandemic and remained low following implementation of prevention efforts, including mask mandates and school closures, according to data published in JAMA Network Open.
“Public health measures implemented during the COVID-19 pandemic had widespread effects on population behaviors, transmission of infectious diseases, and exposures to environmental pollutants,” Jennifer A. Burney, PhD, of the School of Global Policy and Strategy at the University of California, in San Diego, and co-authors wrote. “This provided an opportunity to study how these factors potentially influenced the incidence of Kawasaki disease (KD), a self-limited pediatric vasculitis of unknown etiology.”
In order to investigate the impact of the COVID-19 pandemic on KD, Burney and colleagues conducted a multicenter study with patients diagnosed between Jan. 1, 2018, and Dec. 31, 2020. All patients from 28 pediatric centers who met the American Heart Association criteria for “complete or incomplete” KD were included in the analysis. The date of disease onset was defined as the first day the patient had a fever and was reported monthly for all patients, the authors wrote. Data including age at disease onset, patient-reported race and ethnicity, GPS position of the patients’ homes and clinical evaluation details were recorded prospectively.
Researchers used data provided by Safegraph, as well as publicly available mobile phone data regarding public health orders, to analyze the mobility patterns of residents in Southern California between January 2019 and April 2021. Data quantified how much time residents spent away from home and allowed researchers to evaluate whether neighborhoods with KD were sheltering in place more, or less, effectively. Additionally, pollution data from January 2019 through October 2021, and common virus circulating patterns were analyzed.
In all, 2,461 cases of patients with KD were included from the multicenter study, in addition to 1,461 cases from the Rady Children’s Hospital San Diego (RCHSD) from 2002 through 2021. There was a 28.2% national reduction in KD cases in 2020 compared with 2018 and 2019, but the difference was varied across the U.S., the authors wrote. In addition, mobility data did not appear to impact overall KD numbers. The decreased KD rates appeared to correlate with school closures, mask mandates, lower transmission of respiratory viruses and lower levels of pollution. In San Diego, KD case numbers rebounded in 2021, suggesting a correlation with the end of mask mandates in the area, the authors wrote.
“In this study of KD incidence in the United States between 2018 and 2020, the national and local (San Diego region) reduction in KD cases was associated with a period of school closures, masking mandates, decreased ambient pollution and decreased circulation of respiratory viruses, which all overlapped to different extents with the period of decreased KD cases,” Burney wrote. “The observations presented here suggest several productive avenues for research into the etiology of KD.”
The authors added, “The pandemic has shown that limiting exposures to aerosols and large droplets through some combination of masking, social distancing, and hand hygiene can reduce the incidence of KD in diverse communities throughout the globe.”