Impact of the Coronavirus Disease 2019 Pandemic on the Clinical Features of Pediatric Respiratory Syncytial Virus Infection in Japan

Shoko Ozeki; Jun-Ichi Kawada; Daiki Yamashita; Chika Yasufuku; Takuya Akano; Masahiro Kato; Konomi Suzuki; Chihiro Tano; Kazuki Matsumoto; Shu-Hei Mizutani; Ayumi Mori; Nobuhiro Nishio; Hiroyuki Kidokoro; Yoshihiro Yasui; Yoshiyuki Takahashi; Yoshiaki Sato; Nagoya Collaborative Clinical Research Team

doi:10.1093/ofid/ofac562

Impact of the Coronavirus Disease 2019 Pandemic on the Clinical Features of Pediatric Respiratory Syncytial Virus Infection in Japan

Open Forum Infect Dis. 2022 Oct 22;9(11):ofac562. doi: 10.1093/ofid/ofac562. eCollection 2022 Nov.

Authors

Shoko Ozeki¹, Jun-Ichi Kawada¹, Daiki Yamashita¹, Chika Yasufuku¹, Takuya Akano¹, Masahiro Kato¹, Konomi Suzuki¹, Chihiro Tano¹, Kazuki Matsumoto¹, Shu-Hei Mizutani¹, Ayumi Mori¹, Nobuhiro Nishio^{1

2}, Hiroyuki Kidokoro¹, Yoshihiro Yasui³, Yoshiyuki Takahashi¹, Yoshiaki Sato^{1

4}; Nagoya Collaborative Clinical Research Team

Collaborators

Nagoya Collaborative Clinical Research Team:
Anna Shiraki, Kazuto Ueda, Shotaro Ando, Noriko Nagai, Tsutomu Aoshima, Michio Suzuki, Tetsuo Kubota, Motomasa Suzuki, Satoru Doi, Daichi Fukumi, Yuichiro Sugiyama, Masafumi Morishita, Naoko Nishimura, Mizuki Takagi, Hirokazu Kurahashi, Yohei Takeuchi, Kenji Kuraishi, Osamu Shinohara, Takashi Kawabe, Nobuhiro Watanabe, Shinji Hasegawa, Taichiro Muto, Shinji Kido, Shinya Hara, Shin Hoshino

Affiliations

¹ Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan.
² Department of Advanced Medicine, Center for Advanced Medicine and Clinical Research, Nagoya University Hospital, Nagoya, Japan.
³ Department of Surveillance and Information, Aichi Prefectural Institute of Public Health, Nagoya, Japan.
⁴ Division of Neonatology, Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Japan.

Abstract

Background: Mitigation measures implemented during the coronavirus disease 2019 (COVID-19) pandemic remarkably reduced the incidence of infectious diseases among children. However, a re-emergence of respiratory syncytial virus (RSV) infection was observed in 2021 in Japan. We compared the clinical characteristics of hospitalized patients with RSV infection before and during COVID-19.

Methods: We retrospectively enrolled children aged <6 years who were hospitalized with RSV infection in 18 hospitals and compared their clinical characteristics before (January 2019 to April 2020, 1675 patients) and during COVID-19 (September 2020 to December 2021, 1297 patients).

Results: The mean age of patients with RSV infection was significantly higher during COVID-19 than before (17.4 vs 13.7 months, P < .001). Compared with before COVID-19, a 2.6-fold increase in RSV cases in the 2-5 years age group was observed from sentinel surveillance during COVID-19, whereas a 1.2-fold increase was noted in the same age group among hospitalized patients. On average for all patients, consolidation shadows obtained on radiography were less frequently observed (26.1 vs 29.6%, P = .04), and reduced respiratory assistance (42.2% vs 48.7%, P < .001) and hospitalization stay (5.7 vs 6.0 days, P < .001) was required in patients with RSV infection during COVID-19.

Conclusions: Coronavirus disease 2019 and social activity restriction caused epidemiological changes in pediatric RSV infections, and a majority of patients with RSV infection aged ≥2 years did not develop severe symptoms requiring hospitalization. The RSV symptoms during the COVID-19 outbreak were equivalent to or milder than in the previous seasons.

Keywords: COVID-19; RSV; SARS-CoV-2; pediatric.