The relationship between new PCR positive cases and going out in public during the COVID-19 epidemic in Japan

PLoS One. 2022 May 26;17(5):e0266342. doi: 10.1371/journal.pone.0266342. eCollection 2022.

Abstract

The suppression of the first wave of COVID-19 in Japan is assumedly attributed to people's increased risk perception after acquiring information from the government and media reports. In this study, going out in public amidst the spread of COVID-19 infections was investigated by examining new polymerase chain reaction (PCR) positive cases of COVID-19 and its relationship to four indicators of people going out in public (the people flow, the index of web searches for going outside, the number of times people browse restaurants, and the number of hotel guests, from the Regional Economic and Social Analysis System (V-RESAS). Two waves of COVID-19 infections were examined using cross-correlation analysis. In the first wave, all four indicators of going out changed to be opposite the change in new PCR positive cases, showing a lag period of -1 to +6 weeks. In the second wave, the same relationship was only observed for the index of web searches for going outside, and two indicators showed the positive lag period of +6 to +12 weeks after the change in new PCR positive cases. Moreover, each indicator in the second wave changed differently compared to the first wave. The complexity of people's behaviors around going out increased in the second wave, when policies and campaigns were implemented and people's attitudes were thought to have changed. In conclusion, the results suggest that policies may have influenced people's mobility, rather than the number of new PCR positive cases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19* / epidemiology
  • Epidemics*
  • Humans
  • Japan / epidemiology
  • Polymerase Chain Reaction
  • SARS-CoV-2 / genetics

Grants and funding

This work was supported by JSPS KAKENHI (Grant Number JP19H01075) from the Japan Society for the Promotion of Science (https://www.jsps.go.jp/english/e-grants/), and by the GAP Fund Program of Kyoto University, GAP Fund Program Type B (http://www.venture.saci.kyoto-u.ac.jp/?page_id=83#gp) to Y. I. The funders played no role in the study design, data collection and, data management, analysis, decision to publish, preparation, review and approval of the manuscript.