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Coronaviruses

International Travel Controls and COVID-19 Outbreak Progression: A Global Analysis

Strategic Insights

— 2 min read

In the early stages of the COVID-19 pandemic, the World Health Organization (WHO) did not recommend restricting travel, and travel controls had not been widely used in previous pandemics. However, as the number of cases continued to rise, countries began to implement international travel controls to slow the spread of the virus. This study examines the association between the implementation of international travel controls and local COVID-19 outbreak progression in 165 countries.

Key Takeaways:

  • Only 14 (8.5%) of the 165 countries studied enacted international travel controls coincident with the lockdown in Wuhan, China, and all controls involved screening inbound travelers.
  • Enactment of international travel controls peaked 3 weeks after the WHO declared the pandemic, with 112 (67.8%) countries completely closing their borders, 44 (26.6%) banning travelers from high-risk regions, and 4 (2.4%) requiring quarantine for travelers from high-risk regions.
  • Countries that had enacted any international travel controls before their first COVID-19 case reported their first case a median of 57 days later than countries that imposed their strongest controls after the first case was reported.
  • After adjusting for population density and nonpharmaceutical interventions, the average time to detection of the first case occurred 1.22 times later in countries that implemented any restrictions than in countries that implemented no travel restrictions.
  • The time to peak death and cumulative incidence rates was also delayed in countries that implemented international travel controls, but the strongest controls were not associated with a reduced time to peak death or cumulative incidence of 5 cases/100,000 persons.
  • The study found that implementing international travel controls earlier delayed the initial epidemic peak by 5 weeks, suggesting that delaying the introduction of the virus bought valuable time for local health systems and governments to prepare to respond to local transmission.

Statistics:

  • 14 (8.5%) of the 165 countries studied enacted international travel controls coincident with the lockdown in Wuhan, China.
  • 112 (67.8%) countries completely closed their borders, 44 (26.6%) banned travelers from high-risk regions, and 4 (2.4%) required quarantine for travelers from high-risk regions.
  • Countries that had enacted any international travel controls before their first COVID-19 case reported their first case a median of 57 days (95% CI 14-70) later than countries that imposed their strongest controls after the first case was reported.
  • The average time to detection of the first case occurred 1.22 (95% CI 1.06-1.41) times later in countries that implemented any restrictions than in countries that implemented no travel restrictions.
  • The time to peak death and cumulative incidence rates was delayed in countries that implemented international travel controls, with a delay of 5 weeks (95% CI 3-7 weeks) in the initial epidemic peak.

Sources:

  • World Health Organization (WHO)
  • Department of Health of the Food and Health Bureau of the Government of Hong Kong
  • Health and Medical Research Fund, Food and Health Bureau and Government of the Hong Kong Special Administrative Region (grant no. COVID190118)
  • WHO Collaborating Centre for Reference and Research on Influenza
  • Australian Government Department of Health
  • Roche
  • GSK
  • Moderna
  • AstraZeneca
  • Sanofi Pasteur
  • Sequiris
  • US Department of Health and Human Services
  • Public Health Service
  • Centers for Disease Control and Prevention

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