Impact of the State of Emergency during the COVID-19 Pandemic in 2020 on Asthma Exacerbations among Children in Kobe City, Japan

Abstract

The coronavirus disease (COVID-19) pandemic altered environmental factors. We studied the impact of these changes on asthma exacerbation (AE) by comparing the AE-related environmental factors between COVID-19 (2020) and pre-COVID-19 (2011-2019) eras. Between 2011 and 2020, 278,465 children (<16 years old) visited our emergency department, and 7476 were diagnosed with AE. The number of patients showed spring and fall peaks in 2011-2019. Multivariate analyses showed significant positive relationships of the number of AE patients with the average temperature among all patients and 0-5-year-olds and with sulfur dioxide (SO₂) levels in 2011-2019 among 0-5-year-olds. Although the spring peak in the number of patients was not observed in 2020 after declaration of a state of emergency, the fall peak was again observed after the state of emergency was lifted. No changes in average temperature were detected, but SO₂ was significantly reduced following declaration of the state of emergency in 2020. Therefore, SO₂ reduction might have contributed to the disappearance of the peak of AE. However, a fall peak was observed again in 2020, although SO₂ levels continued to be low. These data suggest that person to person interaction seems to be associated with AE, presumably due to unknown viral infections.