Exploring the threshold for the start of respiratory syncytial virus infection epidemic season using sentinel surveillance data in Japan

Takeshi Miyama; Kensaku Kakimoto; Nobuhiro Iritani; Takayuki Nishio; Tomohiko Ukai; Yuka Satsuki; Yasutaka Yamanaka; Yoko Nishida; Ayumi Shintani; Kazushi Motomura

doi:10.3389/fpubh.2023.1062726

Exploring the threshold for the start of respiratory syncytial virus infection epidemic season using sentinel surveillance data in Japan

Front Public Health. 2023 Feb 3:11:1062726. doi: 10.3389/fpubh.2023.1062726. eCollection 2023.

Authors

Affiliations

¹ Epidemiology Section, Division of Public Health, Osaka Institute of Public Health, Osaka, Japan.
² Emergency Preparedness and Response Section, Division of Public Health, Osaka Institute of Public Health, Osaka, Japan.
³ Department of Medical Statistics, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan.

Abstract

Introduction: An unusual seasonality of respiratory syncytial virus (RSV) infection in Japan is observed in recent years after 2017, becoming challenging to prepare for: a seasonal shift from autumn-winter to summer-autumn in 2017-2019, no major epidemic in 2020, and an unusually high number of cases reported in 2021.

Methods: To early detect the start-timing of epidemic season, we explored the reference threshold for the start-timing of the epidemic period based on the number of cases per sentinel (CPS, a widely used indicator in Japanese surveillance system), using a relative operating characteristic curve analysis (with the epidemic period defined by effective reproduction number).

Results: The reference values of Tokyo, Kanagawa, Osaka, and Aichi Prefectures were 0.41, 0.39, 0.42, and 0.24, respectively.

Discussion: The reference CPS value could be a valuable indicator for detecting the RSV epidemic and may contribute to the planned introduction of monoclonal antibody against RSV to prevent severe outcomes.

Keywords: Japan; early epidemic detection; effective reproduction number; epidemic threshold; epidemiology; prevention; relative operating characteristic curve analysis; respiratory syncytial virus (RSV).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Humans
Japan / epidemiology
Respiratory Syncytial Virus Infections* / diagnosis
Respiratory Syncytial Virus Infections* / epidemiology
Respiratory Syncytial Virus, Human*
Seasons
Sentinel Surveillance

Grants and funding

This work was supported by the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for Scientific Research [KAKENHI JP19K24219 and JP22K17410 to TM]. The funder had no role in the analysis and interpretation of this study.