Strategies at points of entry to reduce importation risk of COVID-19 cases and reopen travel

J Travel Med. 2020 Dec 23;27(8):taaa141. doi: 10.1093/jtm/taaa141.

Abstract

Background: With more countries exiting lockdown, public health safety requires screening measures at international travel entry points that can prevent the reintroduction or importation of the severe acute respiratory syndrome-related coronavirus-2. Here, we estimate the number of cases captured, quarantining days averted and secondary cases expected to occur with screening interventions.

Methods: To estimate active case exportation risk from 153 countries with recorded coronavirus disease-2019 cases and deaths, we created a simple data-driven framework to calculate the number of infectious and upcoming infectious individuals out of 100 000 000 potential travellers from each country, and assessed six importation risk reduction strategies; Strategy 1 (S1) has no screening on entry, S2 tests all travellers and isolates test-positives where those who test negative at 7 days are permitted entry, S3 the equivalent but for a 14 day period, S4 quarantines all travellers for 7 days where all are subsequently permitted entry, S5 the equivalent for 14 days and S6 the testing of all travellers and prevention of entry for those who test positive.

Results: The average reduction in case importation across countries relative to S1 is 90.2% for S2, 91.7% for S3, 55.4% for S4, 91.2% for S5 and 77.2% for S6. An average of 79.6% of infected travellers are infectious upon arrival. For the top 100 exporting countries, an 88.2% average reduction in secondary cases is expected through S2 with the 7-day isolation of test-positives, increasing to 92.1% for S3 for 14-day isolation. A substantially smaller reduction of 30.0% is expected for 7-day all traveller quarantining, increasing to 84.3% for 14-day all traveller quarantining.

Conclusions: The testing and isolation of test-positives should be implemented provided good testing practices are in place. If testing is not feasible, quarantining for a minimum of 14 days is recommended with strict adherence measures in place.

Keywords: Lockdown; SARS-CoV-2; air passengers; border measures; isolation; quarantine; travel restrictions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Travel / statistics & numerical data
  • Airports / organization & administration
  • COVID-19 Testing / methods*
  • COVID-19* / diagnosis
  • COVID-19* / epidemiology
  • COVID-19* / prevention & control
  • Communicable Disease Control* / legislation & jurisprudence
  • Communicable Disease Control* / organization & administration
  • Communicable Diseases, Imported* / diagnosis
  • Communicable Diseases, Imported* / epidemiology
  • Communicable Diseases, Imported* / prevention & control
  • Epidemiological Monitoring
  • Global Health
  • Humans
  • Mass Screening / methods*
  • Quarantine / methods*
  • Risk Assessment / methods
  • Risk Assessment / statistics & numerical data
  • SARS-CoV-2 / isolation & purification*