Disease burden of respiratory syncytial virus infection in the pediatric population in Japan.

INTRODUCTION: Respiratory syncytial virus (RSV) is one of the most common causes of lower respiratory tract infections in children aged <5 years and is associated with long-term respiratory morbidities such as recurrent wheezing and asthma, decreased lung function, and allergic sensitization. The objective of this review was to evaluate the epidemiology and burden of RSV infection in the pediatric population in Japan.

METHODS: Studies indexed in PubMed and ICHUSHI databases during January 2010-December 2020 were manually reviewed. Data on proportion of RSV infections, seasonality, length of stay (LoS), mortality, medical expenses, and palivizumab use were extracted from the selected articles.

RESULTS: Ninety-three articles were included (PubMed, 64; ICHUSHI, 29). The proportion of patients/samples with an RSV infection was 5.5%-66.7%, and 6.0%-29.9% in the inpatient and outpatient departments, respectively. RSV infections generally occurred during autumn/winter; however, recently the peak has shifted to summer. The LoS was variable and depended on factors such as age, infection severity, wheezing, and RSV subgroups. Mortality rates varied from <1% to 19% depending on the infection severity. The average daily hospitalization and intensive care unit cost was JPY 34,548 while intensive care unit incurred an additional cost of JPY 541,293. Palivizumab was indicated for high-risk infants and 0%-3% of patients required hospitalization despite palivizumab use.

CONCLUSIONS: RSV imposes a significant burden on the Japanese healthcare system, suggesting a need to create awareness among caregivers of children, pregnant women and healthcare professionals to ensure early recognition of infection and adequate treatment or prophylaxis.