International travel volumes have now fully recovered from the downturn during the COVID-19 pandemic. With the upcoming World Cup poised to drive a surge in Canadian tourism, recent hantavirus and Ebola virus outbreaks remind us of the need to effectively manage travel-related public health risks in a world on the move.
Both outbreaks underscore how human mobility can play a critical role in the spread of deadly diseases, including pathogens with pandemic potential. As researchers on the Pandemics and Borders Project, we have spent the past six years studying the use of international travel measures in response to the COVID-19 pandemic and other global public health emergencies. Lessons from COVID-19 on the effective use of international travel measures in managing serious infectious disease outbreaks are critical to ongoing pandemic readiness.
Key lessons from COVID-19 travel measures
COVID-19 upended previous scientific consensus that restricting international travel, to prevent cross-border spread of disease, should be an action of last resort. Restrictions were thought to yield limited, if any, public health benefits for most outbreaks. It is now recognized that:
- Travel measures extend beyond restrictions or bans, and include: screening (for example, testing), quarantine and vaccination;
-
Early, stringent use of
certain international travel measures
— such as those adopted by New Zealand, Singapore and South Korea — was effective in slowing or reducing the introduction and spread of SARS-CoV-2 and its variants;
- International travel measures adopted by governments were highly varied, poorly co-ordinated and ever-changing, leading to sub-optimal public health outcomes;
- International travel measures can lead to secondary social and economic impacts that may be costly, inequitably distributed and politically divisive; and
- International consensus is needed on appropriate risk-based approaches. These must account for the specific pathogens, varying national contexts, risks beyond public health and different types of travel measures.
Above all, COVID-19 underscored the need for better international co-ordination of risk-based approaches to travel and border management when responding to infectious disease outbreaks and pandemic threats. The complexity of whether, when and how to apply different types of international travel measures means that evidence on best practices continues to evolve.
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Applying lessons to hantavirus and Ebola
Recent outbreaks of hantavirus among passengers of the MV Hondius cruise ship, and Ebola in the Democratic Republic of the Congo (DRC) and Uganda, have raised concerns about risks associated with travel. With varied national responses to these risks, how can we apply lessons from COVID-19 to guide effective public health responses?
With 13 reported cases, including three deaths to date, the recent hantavirus outbreak was reported to the World Health Organization (WHO) on May 2, following the medical evacuation of a passenger from the MV Hondius.
Of the 147 people on board the cruise ship, 88 passengers were citizens of high-income countries. These governments quickly mobilized chartered-flight evacuations of nationals, followed by isolation and ongoing monitoring for symptoms. The ship’s crew, from countries including the Philippines, India and Guatemala, were either evacuated or continued on to the Netherlands to quarantine before returning home.
Rapid response to travel-related risks of hantavirus was adequately resourced, globally co-ordinated and appears so far to have balanced the need for protecting the health of MV Hondius passengers while preventing the wider health-harming spread of disease.
Response to the outbreak of what has been identified as Bundibugyo virus disease (BVD) is a very different, albeit familiar, story. This outbreak is affecting primarily poor and under-resourced communities in rural areas of the DRC and Uganda.
As a less common strain of Ebola, Bundibugyo virus had likely been spreading undetected for some time before being reported to WHO. It has since been declared a Public Health Emergency of International Concern.
Existing medical interventions and testing for Ebola are less effective against BVD than other Ebola viruses. As a result, response to this outbreak is in some ways “back at square one.”
Amid evolving evidence on best practices, some travel measures adopted in response to BVD diverge from what is currently known about how to effectively manage travel-related health risks. For example, United States restrictions for travellers from three East African countries resulted in the diversion of a U.S.-bound plane to Montréal after a Congolese passenger was denied entry.
Yet, in a highly mobile and interconnected world, singling out travellers based on nationality makes little sense from an epidemiological perspective. As seen during the COVID-19 pandemic, these often politically motivated measures can also fuel harmful divisiveness, racism and discrimination.
Better co-ordinated, risk-based approaches
Stark differences in hantavirus and Ebola responses stem partly from longstanding fault lines in global systems for preventing the international spread of infectious disease. Amid expert reassurances that these events do not pose pandemic threats, COVID-19 lessons underscore that our collective ability to manage travel-related public health risks is an important predictor of future effectiveness.
In a hypermobile and globalized world, the spread of pathogens is an ongoing threat.
Different types of travel measures, deployed in a timely and appropriate manner, can be effectively used to control outbreaks — including those of fast-moving, novel and highly transmissible pathogens with pandemic potential. These case studies remind us that the capacity of governments to make co-ordinated, risk-based, real-time decisions about travel measures remains an ongoing challenge.
This article was originally published on The Conversation. Read the original article.
