15 Mar 2021

Evidence of the effectiveness of travel-related measures during the early phase of the COVID-19 pandemic: a rapid systematic review

There is limited evidence to inform the effectiveness travel measures against outbreaks such as influenza. The different clinical feature of COVID-19 makes the virus more difficult to detect and contain compared with other infectious diseases; hence, raising the question on whether travel-related measures are effective against the virus. A team of HKUMed experts performed a systematic review of 29 studies to ascertain the effectiveness of travel measures adopted during the early phase of the COVID-19 pandemic.


Key takeaways from the review:

  • The studies showed that adopting travel measures early played an important role in shaping the early transmission dynamics of COVID-19.
  • Wuhan travel restrictions led to an estimated 70%–80% reduction in exported cases. This reduction was 10%–70% within Mainland China.
  • The Wuhan travel ban also delayed the importation of new cases to other countries by a few weeks. However, over time, other provinces became the source of most internationally exported cases.
  • Reduction in flight numbers also reduced the number of imported cases.
  • The timing of intervention impacts the effectiveness of it. The reviewers ascertained that had the same travel measures been implemented a few weeks earlier, the spread of the virus across China and internationally would have been reduced.
  • The reviewers concluded that the overall quality of the studies was low, as the results that depended on important parameter assumptions varied considerably.


Although the quality of evidence was low, this review identified new evidence that early travel measures could impact the dynamics of the COVID-19 pandemic. However, more research is needed to understand the role of travel measures to curb the spread of a novel infectious disease outbreak.


To read the original article published in BMJ Global Health, click here.