According to the study, published in JAMA Network Open Pediatrics, researchers found that Kawasaki disease cases fell by 28 percent in 2020 and remained low during the peak pandemic period.
The drop was associated with school closures, masking mandates, decreased ambient air pollution and reduced circulation of respiratory viruses. Kawasaki disease cases rebounded in the spring of 2021, coinciding with the lifting of masking mandates and the return of in-person schooling.
While this condition affects less than 6,000 children each year, the disease continues to puzzle pediatricians, as its exact trigger(s) and mode of entry into the body have yet to be identified. Unlike COVID-19, Kawasaki disease is not contagious.
However, the discovery that precautions against coronavirus were effective in reducing Kawasaki disease suggests its trigger(s) are similarly inhaled into the upper respiratory tract.
The results from the analysis showed that the rates of Kawasaki disease are typically higher in male and Asian children, and these groups saw especially large drops in cases during the pandemic.
Another group that saw a disproportionate decrease was children ages one through five. This was notable when compared to infants, who saw no significant change in Kawasaki disease rates during this time period. The reason is likely because infant behavior was not as significantly impacted by the pandemic while typical activities and exposures for older children changed more dramatically.
Therefore, the authors concluded that the patterns suggested that social behavior affects exposure to the agent(s) that trigger KD, and are consistent with a respiratory portal of entry.