Open this photo in gallery The impact of releasing passengers of the Ruby Princess cruise ship – New South Wales police seen here boarding the Ruby Princess on April 8, 2020 – into Australia has not led to multicentered clusters of community outbreak. NSW POLICE/Reuters

At the University of Melbourne, professor Nancy Baxter is head of the Melbourne School of Population and Global Health, and professor Shitji Kapur is Dean of the Faculty of Medicine, Dentistry and Health Sciences. Professor Joel Negin is head of the Sydney School of Public Health at the University of Sydney. The authors have all worked in both Canada and Australia

The two countries have much in common: beautiful scenery, vast spaces, sparse populations, big metropolitan cities with lots of international travellers, and well-funded health systems.

In the beginning, Canada and Australia also shared a similar COVID-19 experience, but began to differ from each other in dramatic ways at the end of March. Studying these differences may provide important lessons for responding to pandemics in the future.

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Both countries discovered their first cases on January 25. By the end of February, Australia had 25 cases, Canada 20. Most of these cases were clustered in large metropolitan cities for both, and by March 25, each country had about 3,000 people who had tested positive.

Then something changed dramatically. As of Friday afternoon, Australia has slightly more than 6,500 cases – Canada has more than 30,000. Over the last week, Australia added 383 new cases while Canada has added around 1,000 to its total every day. There have been about 66 coronavirus-related deaths in Australia, while Canada has lost nearly 1,200 people to the disease.

Both countries have implemented physical distancing measures with imperfect success: In mid-March, large weddings were held in Montreal and crowds enjoyed the sun at Sydney’s Bondi Beach, necessitating increased restrictions and enforcement. Both countries were also testing for COVID-19 at similar rates (although Australia’s testing-per-million ratio has since pulled ahead of Canada’s). But by the end of the month, the number of daily new cases began to decline in Australia just as the number began to dramatically increase in Canada. Why have the paths of these two countries with seemingly similar approaches to the pandemic diverged?

Most of Australia’s early cases were imported from overseas travellers and passed onto their direct contacts. Those arriving by plane or boat were relatively easy to track through a rigorous contact-tracing endeavour, which is more difficult to accomplish when travellers cross a long border (such as the one separating Canada and the United States) by car. Few cases in Australia originated in China, since the former country moved quickly to ban travel from the latter. In fact, most importations arrived from Europe and the United States, with many, notably, originating on cruise ships. On March 15, two weeks before new cases of COVID-19 began to decline in Australia, all travellers arriving in the country were “required” to self-isolate for 14 days.

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In comparison, self-isolation for return travellers was only “advised” in Canada until March 25. That is the period when many Canadian families returned home from their March Break trips, as did many of the snowbirds who spend their winters in Florida. Perhaps because of these lax instructions, and the seamlessness of travel from the U.S., returning Canadians spread the virus throughout their communities. In Australia, community transmission has only accounted for about 10 per cent of COVID-19 cases; in Canada this rate is close to 75 per cent. And the spread of the virus into at least 600 retirement and nursing homes in Canada – perhaps accounting for the strikingly different death toll – is a fate Australians have been spared to date.

That said, the picture differs state by state in Australia, as it differs province by province in Canada. New South Wales accounts for nearly half of Australian cases, and half of those are in the state capital of Sydney. Similarly, a quarter of positive cases in Canada reside in one city, Montreal. In Quebec, the health system is struggling, intraprovincial travel has been restricted, and the army has been called on to support the northern part of the province. Things are much different in British Columbia, where new cases are declining and where COVID-19 testing per capita is happening at a high rate.

The comparison shows how perilous managing a pandemic is. There is a degree of luck and circumstances. The impact of releasing passengers of the Ruby Princess cruise ship into Australia has not led to multicentered clusters of community outbreak, while the spread of COVID-19 to a retirement home in Bobcaygeon, Ont., has led to 29 deaths. A few days of movement here or there can make all the difference.

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In the future, stating that self-isolation after travel in the midst of a pandemic is a “requirement” as opposed to an “advisory” measure – even though neither has been enforced punitively – may work to change people’s behaviour. Whether a pandemic spreads to long-term care homes may also dramatically change the death toll.

Strict quarantine of travellers and protection of long-term care facilities are key lessons Australia can learn from Canada’s crisis, while Canada’s current challenge is to regain control over its recent surge of cases.

Now that it is recommended you wear a face covering in dense public settings like grocery stores and pharmacies, watch how to make the three masks recommended by the Centers for Disease Control and Prevention. Written instructions available at tgam.ca/masks The Globe and Mail

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