Prevalence of β-agonist inhalation for outpatients in a pediatric emergency center during enterovirus D68 epidemic.

Background: Enterovirus D68 (EV-D68) has been reported to have caused severe bronchial asthma attacks and hospitalization epidemics in Japan in September 2015.

Objective: To investigate the prevalence of β-agonist inhalation in a pediatric emergency center during a period of increased hospitalization for bronchial asthma, which was suggested to be associated with EV-D68.

Methods: We investigated the prevalence of β-agonist inhalation in a pediatric emergency center in Saga city, Japan, from April 2013 to October 2015, and also clarified the trends in bronchial asthma hospitalization in the same area during that time.

Results: The prevalence of β-agonist inhalation in the pediatric emergency center, September 2015 was highest when EV-D68 became widespread. The monthly average for β-agonist inhalation during the study period was 91 cases, but the count in September 2015 was 255 cases. Hospitalized cases of bronchial asthma in September 2015 were increased for age ≥3 years and not increased for age <3 years, but the prevalence of β-agonist inhalation at the pediatric emergency center was increased even under the age of 3 years.

Conclusion: During the epidemic period for EV-D68, cases requiring β-agonist inhalation were increased. The EV-D68 epidemic may be related to not only severe cases requiring hospitalization, but also exacerbation of relatively mild symptoms of bronchial asthma.