Miyama Takeshi, Kakimoto Kensaku, Yamanaka Yasutaka, Nishida Yoko, Iritani Nobuhiro, Motomura Kazushi
Epidemiology Section, Division of Public Health, Osaka Institute of Public Health, Osaka, Japan.
Emergency Preparedness and Response Section, Division of Public Health, Osaka Institute of Public Health, Osaka, Japan.
IJID Reg. 2024 Sep 5;13:100442. doi: 10.1016/j.ijregi.2024.100442. eCollection 2024 Dec.
Owing to the nonpharmaceutical interventions against COVID-19, respiratory syncytial virus (RSV) infection was nearly absent in 2020. An unusual epidemic size and irregular seasonal pattern were observed worldwide in 2021. In Osaka, Japan, after disrupting the regular pattern of RSV infection dynamics (before the COVID-19 pandemic, RSV epidemics typically start in summer and peak around fall), the epidemic size of RSV infection returned to normal in 2022. However, the epidemic onset timing remained irregular in 2022 and 2023. This study investigated whether the onset of the RSV infection epidemic in 2023 was predictable using previous seasonal patterns.
The weekly number of RSV infection cases obtained from sentinel pediatric sites between 2007 and the 15th week of 2023 was modeled using the time series susceptible-infected-recovered model. Forecasting of the remainder of 2023 was conducted based on estimated transmission parameters.
None of the estimated transmission rates from previous years successfully forecast the epidemic onset in 2023. Only the transmission rate estimated in the early part of 2023 captured the trend for that year, indicating irregular seasonal transmission rates.
It is still hard to forecast RSV epidemics because of the changed landscape due to the COVID-19 pandemic. The seasonality of RSV infection dynamics has not returned to pre-pandemic level in 2023. Cautious attention to future RSV dynamics in Japan is warranted because further changes may occur in the near future.
由于针对新冠病毒病的非药物干预措施，呼吸道合胞病毒（RSV）感染在2020年几乎不存在。2021年在全球范围内观察到异常的流行规模和不规则的季节性模式。在日本大阪，在打乱RSV感染动态的常规模式后（在新冠病毒病大流行之前，RSV流行通常在夏季开始并在秋季左右达到高峰），RSV感染的流行规模在2022年恢复正常。然而，2022年和2023年的流行发病时间仍然不规则。本研究调查了能否利用先前的季节性模式预测2023年RSV感染流行的发病情况。
使用时间序列易感-感染-恢复模型对2007年至2023年第15周从哨点儿科场所获得的RSV感染病例周数进行建模。基于估计的传播参数对2023年剩余时间进行预测。
往年估计的传播率均未成功预测2023年的流行发病情况。只有2023年上半年估计的传播率捕捉到了当年的趋势，表明季节性传播率不规则。
由于新冠病毒病大流行导致情况发生变化，仍然难以预测RSV流行。2023年RSV感染动态的季节性尚未恢复到大流行前的水平。鉴于近期可能会发生进一步变化，有必要谨慎关注日本未来的RSV动态。
