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

• Published in: Open forum infectious diseases Vol. 9; no. 11; p. ofac562
• Main Authors: Ozeki, Shoko, Kawada, Jun-ichi, Yamashita, Daiki, Yasufuku, Chika, Akano, Takuya, Kato, Masahiro, Suzuki, Konomi, Tano, Chihiro, Matsumoto, Kazuki, Mizutani, Shu-hei, Mori, Ayumi, Nishio, Nobuhiro, Kidokoro, Hiroyuki, Yasui, Yoshihiro, Takahashi, Yoshiyuki, Sato, Yoshiaki, Shiraki, Anna, Ueda, Kazuto, Ando, Shotaro, Nagai, Noriko, Aoshima, Tsutomu, Suzuki, Michio, Kubota, Tetsuo, Suzuki, Motomasa, Doi, Satoru, Fukumi, Daichi, Sugiyama, Yuichiro, Morishita, Masafumi, Nishimura, Naoko, Takagi, Mizuki, Kurahashi, Hirokazu, Takeuchi, Yohei, Kuraishi, Kenji, Shinohara, Osamu, Kawabe, Takashi, Watanabe, Nobuhiro, Hasegawa, Shinji, Muto, Taichiro, Kido, Shinji, Hara, Shinya, Hoshino, Shin
• Format: Journal Article
• Language: English
• Published: 01.11.2022
• ISSN: 2328-8957; 2328-8957
• DOI: 10.1093/ofid/ofac562

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.