Changes in the spatiotemporal patterns of COVID-19 in Japan from 2020 through 2023

IF 4.7 3区医学 Q1 INFECTIOUS DISEASES

Journal of Infection and Public Health Pub Date : 2025-02-14 DOI:10.1016/j.jiph.2025.102704

Atsuna Tokumoto , Kazuaki Jindai , Tomoki Nakaya , Mayuko Saito , Clive E. Sabel , Hitoshi Oshitani

{"title":"Changes in the spatiotemporal patterns of COVID-19 in Japan from 2020 through 2023","authors":"Atsuna Tokumoto , Kazuaki Jindai , Tomoki Nakaya , Mayuko Saito , Clive E. Sabel , Hitoshi Oshitani","doi":"10.1016/j.jiph.2025.102704","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><div>The spread of coronavirus disease 2019 (COVID-19) varied among countries. The spatiotemporal trends of COVID-19 in Japan remain understudied. Therefore, this study aimed to conduct a detailed investigation of the spatiotemporal evolution of infections/deaths across prefectures in Japan, to analyze the changing patterns of COVID-19 circulation in metropolitan and nonmetropolitan areas.</div></div><div><h3>Methods</h3><div>We extracted data from nationally represented open-source data from January 15, 2020, to May 9, 2023, and we calculated the incidence rate of infection and the mortality. Further the ratios were obtained by dividing those rates in prefectural level by those in national level to make them comparable across country. Then, the spatiotemporal trends of COVID-19 were depicted via heatmaps. A Poisson regression model was used to compare the incidence rate ratios (IRRs) of infection and death between nonmetropolitan and metropolitan prefectures.</div></div><div><h3>Results</h3><div>During the study period, Japan experienced eight waves of COVID-19 resulting in 33,738,398 confirmed infections and 74,688 deaths. Both infections and deaths increased significantly overtime. Transmission was initially concentrated in metropolitan prefectures. Nonmetropolitan prefectures were protected and had lower numbers of infections and deaths through June 2022. Thereafter, COVID-19 became more widespread, with more localized surges in nonmetropolitan prefectures. Eventually, during the eighth wave (October 16, 2022-May 9, 2023), there was a marked increase in the IRR in nonmetropolitan prefectures reaching 1.25 (95 % confidence interval (CI), 1.15–1.34) for infection and 1.38 (95 % CI, 1.16–1.65) for death.</div></div><div><h3>Conclusions</h3><div>In Japan, COVID-19 transmission was suppressed for the first 2 years of the pandemic, especially in nonmetropolitan prefectures, but the trends changed over time, and more infections and deaths were observed from late 2022 in nonmetropolitan prefectures. These findings underscore the importance of addressing the geographical disparities that likely exist between metropolitan and nonmetropolitan prefectures Delaying large surges in nonmetropolitan prefectures may be an important takeaway that could aid in the future management of major infectious disease outbreaks.</div></div>","PeriodicalId":16087,"journal":{"name":"Journal of Infection and Public Health","volume":"18 5","pages":"Article 102704"},"PeriodicalIF":4.7000,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Infection and Public Health","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S187603412500053X","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"INFECTIOUS DISEASES","Score":null,"Total":0}

引用次数: 0

Abstract

Background

The spread of coronavirus disease 2019 (COVID-19) varied among countries. The spatiotemporal trends of COVID-19 in Japan remain understudied. Therefore, this study aimed to conduct a detailed investigation of the spatiotemporal evolution of infections/deaths across prefectures in Japan, to analyze the changing patterns of COVID-19 circulation in metropolitan and nonmetropolitan areas.

Methods

We extracted data from nationally represented open-source data from January 15, 2020, to May 9, 2023, and we calculated the incidence rate of infection and the mortality. Further the ratios were obtained by dividing those rates in prefectural level by those in national level to make them comparable across country. Then, the spatiotemporal trends of COVID-19 were depicted via heatmaps. A Poisson regression model was used to compare the incidence rate ratios (IRRs) of infection and death between nonmetropolitan and metropolitan prefectures.

Results

During the study period, Japan experienced eight waves of COVID-19 resulting in 33,738,398 confirmed infections and 74,688 deaths. Both infections and deaths increased significantly overtime. Transmission was initially concentrated in metropolitan prefectures. Nonmetropolitan prefectures were protected and had lower numbers of infections and deaths through June 2022. Thereafter, COVID-19 became more widespread, with more localized surges in nonmetropolitan prefectures. Eventually, during the eighth wave (October 16, 2022-May 9, 2023), there was a marked increase in the IRR in nonmetropolitan prefectures reaching 1.25 (95 % confidence interval (CI), 1.15–1.34) for infection and 1.38 (95 % CI, 1.16–1.65) for death.

Conclusions

In Japan, COVID-19 transmission was suppressed for the first 2 years of the pandemic, especially in nonmetropolitan prefectures, but the trends changed over time, and more infections and deaths were observed from late 2022 in nonmetropolitan prefectures. These findings underscore the importance of addressing the geographical disparities that likely exist between metropolitan and nonmetropolitan prefectures Delaying large surges in nonmetropolitan prefectures may be an important takeaway that could aid in the future management of major infectious disease outbreaks.

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of Infection and Public Health PUBLIC, ENVIRONMENTAL & OCCUPATIONAL HEALTH -INFECTIOUS DISEASES

CiteScore

13.10

自引率

1.50%

发文量

203

审稿时长

96 days

期刊介绍： The Journal of Infection and Public Health, first official journal of the Saudi Arabian Ministry of National Guard Health Affairs, King Saud Bin Abdulaziz University for Health Sciences and the Saudi Association for Public Health, aims to be the foremost scientific, peer-reviewed journal encompassing infection prevention and control, microbiology, infectious diseases, public health and the application of healthcare epidemiology to the evaluation of health outcomes. The point of view of the journal is that infection and public health are closely intertwined and that advances in one area will have positive consequences on the other. The journal will be useful to all health professionals who are partners in the management of patients with communicable diseases, keeping them up to date. The journal is proud to have an international and diverse editorial board that will assist and facilitate the publication of articles that reflect a global view on infection control and public health, as well as emphasizing our focus on supporting the needs of public health practitioners. It is our aim to improve healthcare by reducing risk of infection and related adverse outcomes by critical review, selection, and dissemination of new and relevant information in the field of infection control, public health and infectious diseases in all healthcare settings and the community.