At the height of the SARS pandemic of 2003, Toronto fell back on one of the world’s oldest public health tools: quarantines.

City officials identified over 23,000 people who had contact with known or potential Severe Acute Respiratory Syndrome patients, asking nurses, paramedics, high school students, and thousands more to confine themselves to restrict the spread of illness — whether they had symptoms or not.

Today, as Toronto reacts to the outbreak of a novel coronavirus similar to SARS, no one is quarantined. Two confirmed GTA cases are in voluntary “self-isolation” at home, rather than in hospital.

Lessons learned from the SARS crisis have profoundly shaped response to the coronavirus outbreak — including the lesson that rigid and unnecessary restrictions can have serious social, economic and health costs.

Yet the Canadian government is planning to enforce a two-week quarantine at a Canadian Forces Base in Trenton for the 211 apparently healthy people being evacuated Friday from the epicentre of the outbreak in Wuhan, China. Quarantine measures are being invoked worldwide, from the United States, Australia and Hong Kong to a pair of cruise ships anchored in Asia, one of which is carrying at least 251 Canadians.

Infection control experts say there is no health-based reason to justify Ottawa’s quarantine measures. The decision is more likely a political response to a different epidemic: the spread of fear and anxiety.

“Quarantining on the base for 14 days, it’s all optics — it’s all, what do Canadians want to see, and what have other countries done,” says Alon Vaisman, an infection control physician at University Health Network.

Travellers from Wuhan with no symptoms could readily monitor themselves at home, “but the public probably won’t tolerate that.”

“I’m very sympathetic with government,” says Allison McGeer, an infectious disease specialist at the Sinai Health System in Toronto and a veteran of the 2003 SARS outbreak.

“Maybe this is not following science, (and) we know that this is not going to be a benefit ... the benefit is that it won’t generate fear and anger.”

Quarantines were developed in the Middle Ages. In the 14th century, ships arriving in Venice during plague outbreaks were forced to wait for 40 days — or “quaranta giorni,” the root of the English word “quarantine” — before anyone could disembark.

The federal government and the provinces all have legal powers to enforce quarantines, but they are rarely used — both because quarantines restrict individual liberties and because their efficacy is questionable.

“Quarantine is a pretty significant tool, if you will, in the public health tool box, and it’s one that has to be used very carefully,” says Eileen de Villa, Toronto’s medical officer of health.

“When we look at the lessons learned from the various infectious disease outbreaks, and what impacts a variety of different public health tools had on our achieving the objective of reducing transmission, we know these kinds of tools aren’t always the most helpful.”

During SARS, public health officials were operating under a severe information deficit. Over 40 people were infected before the city was aware the virus existed, McGeer notes. Toronto’s first two patients, including a healthy young man, died.

“Nobody was taking any chances,” McGeer says of SARS, which sickened more than 8,000 people globally and killed almost 800, including 44 in Canada.

After one young person became sick, 1,700 high school students were quarantined, according to published research. Over half of Toronto’s 850 paramedics were quarantined. Public health officials obtained 27 mandatory legal quarantine orders.

Many health-care workers were put under “work quarantine,” which required them to travel directly from work to home and make no other stops, and to separate themselves from their families at home and avoid visitors. Nurses and others reported feeling anxious, isolated, and stigmatized, and the quarantines had a major effect on the availability and timeliness of other health services, like surgeries. SARS cost the Canadian economy $4 billion (U.S.) and 28,000 jobs, one report calculated.

“Retrospectively, we did not need to quarantine people,” says McGeer.

A later analysis suggested that quarantining four contacts for every one SARS case would have sufficed; Toronto’s ratio was a hundred to one. But even more crucially, quarantines risk backlash that can undermine disease-control efforts.

When people are afraid they will be restricted or punished for being sick, they are less likely to report symptoms or seek medical attention, experts say. And when sick people are trying to avoid detection, illnesses spread more rapidly.

Quarantines can also increase mortality related to other ailments because the health-care system is over-taxed, notes Vaisman.

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“It takes an immense amount of resources to quarantine a whole neighbourhood. And if it’s all unnecessary, you could have better used those resources to follow up with a suspected case, for example, or put more money into testing, or put more money into education.”

“It’s not bigger, it’s what’s more effective.”

Medical officer de Villa notes that the current response to the coronavirus in Toronto — in which the two known cases are in voluntary self-isolation at home, and no one connected to either those known cases or any cases under investigation are being isolated — is working.

The best way to mitigate the spread of infectious diseases, she says, is to “ensure we set up circumstances that allow for people to do the right thing” — whether that’s handwashing, reporting symptoms, or anything else.

“We find that creating those circumstances requires a certain amount of openness. People have to feel that they’re not going to get punished for coming forward. That’s the balance we have to strike.”

The decision to keep the two confirmed coronavirus patients at home rather than in hospital is also a lesson from SARS, experts say.

“What we learned from SARS is that it was, in Toronto, primarily a hospital or health-care institution outbreak. People got exposed in hospitals, it spread between hospitals due to transfers, and so on,” says Vivek Goel, the founding head of Public Health Ontario, an agency established in the wake of SARS.

“Unless someone really needs to be hospitalized for managing their illness, the last place we want them to be is in the hospital. You’re increasing the risk of exposing other people, and particularly people who may be immunocompromised or have other conditions,” says Goel, who is currently Vice-President of Research and Innovation and a professor of public health at the University of Toronto.

Goel noted that the symptoms of the novel coronavirus outbreak appear to be mild, and that most deaths have occurred in older people and those with underlying health issues.

Infection prevention and control teams at Toronto hospitals were seriously beefed up in the years after SARS, others say. But having a person sick with an infectious disease who doesn’t need to be there is both resource-intensive and creates unnecessary risks.

De Villa notes that voluntary self-isolation at home is a tool that Toronto Public Health uses frequently for other infectious diseases, including tuberculosis, and that it is very effective — people are typically compliant, and don’t want to get anyone else sick.

Patients who don’t need hospital-level care tend to recover more quickly at home in the presence of family and friends, others add, which also helps slow the spread of disease.

The novel coronavirus outbreak has to date infected more than 24,500 people globally, the vast majority in China, and killed almost 500. The Chinese government shut down travel in and out of the province of Hubei, where Wuhan is located, in January, and has since restricted other provinces and cities — a response some have called perhaps the largest public health experiment ever conducted.

“It’s hard to know whether that is going to be effective,” says Vaisman. Something of this scale “has never been done in the history of humanity. So anyone who knows the answer to this question is basing it on zero evidence.”

The Canadian government has said that anyone with symptoms of the virus will not be allowed to board the evacuation flight from Wuhan, and that everyone else will undergo health checks at multiple points on the journey. Health Canada did not respond to questions about the decision to quarantine by publication time, including what medical advice it sought.

Goel notes that the passengers will also have been in the locked-down city of Wuhan for several weeks by the time they arrive at Trenton.

“Is there a health basis for a further two weeks of isolation in the military base? I would suggest not,” he says.

“But given the level of concern in the community, and the fear that is out there, I think it would also be very difficult for the government to not do what it is proposing to do here. The backlash against the government as well as those individuals could be such that this may well be the safest, most reasonable thing.”

He adds, “The fear and the concerns are actually driving a lot of what’s going on, as opposed to necessarily the best health evidence.”

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