Inter-prefectural Travel and Network Connectedness During the COVID-19 Pandemic in Japan

Cyrus Ghaznavi, Daisuke Yoneoka, Yuta Tanoue, Stuart Gilmour, Takayuki Kawashima, Akifumi Eguchi, Yumi Kawamura, Hiroaki Miyata, Shuhei Nomura

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

Background: Increases in human mobility have been linked to rises in novel coronavirus disease 2019 (COVID-19) transmission. The pandemic era in Japan has been characterized by changes in inter-prefectural mobility across state of emergency (SOE) declarations and travel campaigns, but they have yet to be characterized. Methods: Using Yahoo Japan mobility data extracted from the smartphones of more than 10 million Japanese residents, we calculated the monthly number of inter-prefectural travel instances, stratified by residential prefecture and destination prefecture. We then used this adjacency matrix to calculate two network connectedness metrics, closeness centrality and effective distance, that reliably predict disease transmission. Results: Inter-prefectural mobility and network connectedness decreased most considerably during the first SOE, but this decrease dampened with each successive SOE. Mobility and network connectedness increased during the Go To Travel campaign. Travel volume between distant prefectures decreased more than travel between prefectures with geographic proximity. Closeness centrality was found to be negatively correlated with the rate of COVID-19 infection across prefectures, with the strength of this association increasing in tandem with the infection rate. Changes in effective distance were more visible among geographically isolated prefectures (Hokkaido and Okinawa) than among metropolitan, central prefectures (Tokyo, Aichi, Osaka, and Fukuoka). Conclusion: The magnitude of reductions in human mobility decreased with each subsequent state of emergency, consistent with pandemic fatigue. The association between network connectedness and rates of COVID-19 infection remained visible throughout the entirety of the pandemic period, suggesting that inter-prefectural mobility may have contributed to disease spread.

Original languageEnglish
Pages (from-to)510-518
Number of pages9
JournalJournal of epidemiology
Volume32
Issue number11
DOIs
Publication statusPublished - 2022

Keywords

  • COVID-19
  • domestic travel
  • human mobility
  • Japan
  • travel campaign

ASJC Scopus subject areas

  • Epidemiology

Fingerprint

Dive into the research topics of 'Inter-prefectural Travel and Network Connectedness During the COVID-19 Pandemic in Japan'. Together they form a unique fingerprint.

Cite this