In the gloom of the pandemic, nurse Sheila Montague received news on Thursday that brightened her day.

It came from a Western University student in London — a young woman who was the third person to test positive for coronavirus in Ontario, on Jan. 23. She was the first person with COVID-19 that Montague supported while tracing and monitoring the people who came in close contact with the student.

The text message Montague received brimmed with exuberance and gratitude. “She said she was doing well, that she and her partner are still together and that she got her driver’s licence and bought herself a car,” Montague says. “And when all this is over she’s going to pick me up and we’re going for a drive.”

The bit about the boyfriend was a sign that another momentous plan was still on track — the student has promised to invite Montague to her wedding.

“We formed a bond,” says Montague, a nurse at Middlesex-London Health Unit for more than 30 years, adding that the student followed self-isolation and other instructions to the letter.

“The human aspect is so important in the work we do,” she adds in a phone interview. “You don’t want to lose that.”

Montague’s concern about losing the connection she makes with both infected and at-risk people comes as Ontario and the federal government join a growing list of countries exploring the use of cellphone data for “contact tracing.”

“We will develop new technologies for contact tracing and we will all become much better at reacting when a possible resurgence happens,” Prime Minister Justin Trudeau said last weekend.

Contact tracing is vital, labour-intensive gumshoe work done by public health units whenever a communicable disease is detected.

When coronavirus is diagnosed, a physician or lab must by law report the infected person to the local public health unit. A health worker then calls and tells that person to self-isolate for two weeks.

The health worker also asks for contact details of people in close contact with the infected person as far back as 48 hours before the onset of symptoms, says Dr. Shelley Deeks, chief health protection officer at Public Health Ontario. Those close contacts are called, told to self-isolate and to monitor for symptoms.

Everyone is checked on daily by phone, text or social media, and if anyone develops symptoms, the tracing and monitoring process is repeated with their close contacts.

“What we’re trying to do is break the chain of transmission by ensuring that those people who are at the highest risk of exposure are actually self-isolating,” Deeks says.

The Public Health Agency of Canada defines a close contact as anyone who cared for an infected person without consistent use of proper protective equipment; who lived with the person or had “prolonged” contact within two metres while symptoms were present; or was coughed or sneezed on.

A report this week by researchers at Johns Hopkins University and the group representing U.S. public health agencies put the COVID-19 tracing challenge in stark mathematical terms: “It is estimated that each infected person can, on average, infect 2 to 3 others. This means that if 1 person spreads the virus to 3 others, that first positive case can turn into more than 59,000 cases in 10 rounds of infections.”

“COVID-19 can cause large outbreaks quickly, so even 1 missed case can significantly undermine control efforts,” the report adds. It calls for an extra 100,000 contact tracers estimating Congress will need to approve $3.6 billion (U.S.) in funding.

In Wuhan — a Chinese city of 11 million and the epicentre of the outbreak — 9,000 people divided into teams of five were exclusively working on contact tracing when the World Health Organization reported on efforts there in February.

Contact tracing is usually triggered by testing, which in Ontario has lagged. Still, as infections rose, many of Ontario’s 35 public health units scrambled to increase their contact tracing staff. (The 2019 provincial plan to amalgamate and reduce health units to 10 is under review.)

The Middlesex-London Health Unit, for example, had 15 people on its infectious disease team when the Western student became the area’s first case. Within days the unit was using 40 people for contact tracing.

On April 3, Ontario issued an emergency order allowing public health units to boost their contact tracing teams with volunteers. That day, the Middlesex-London unit began training 60 medical students; the unit’s contact tracing staff now has about 120 people. (By April 15, the unit’s area had 250 people infected with the virus, and 12 who had died.)

Also in April, the federal government issued a nationwide call for volunteers, including for work as COVID-19 contact tracers. (Public Health Canada said it does not have figures on the number of contact tracers in the country, and Ontario’s health ministry did not provide statistics.)

Officials with Middlesex-London and Toronto public health units describe Ontario’s centralized health database as inefficient for contact tracing and have developed their own data programs to facilitate tracking.

In the journal Science last week, Oxford University academics argued that “viral spread is too fast to be contained by manual contact tracing” and called for a cellphone app to help.

The attraction of digital technology is the promise of faster tracing and more targeted self-isolation before clusters spread. In enthusiastic comments, Trudeau emphasized its value when blanket stay-home directives are eased.

And in a confidential document revealed by the Star, the provincial government notes it’s considering the use of artificial intelligence and geolocation data from mobile phones to combat the virus.

“There’s huge enthusiasm about this technology,” says professor Ross Upshur, who co-chairs a WHO working group on ethical issues involving the pandemic. “But this needs to be navigated very carefully.”

The enthusiasm extends to the WHO, which recently entertained presentations from a European group flogging such technologies and an AI official from China, says Upshur, who witnessed the presentations. Upshur, who also heads the University of Toronto’s public health division, adds his WHO group is drafting “a guidance document on the ethics of using apps and artificial intelligence in the COVID response.”

Countries including China, South Korea, Singapore and Israel have already used some form of mobile tracking data for contact tracing. Britain has plans for an app and the EU’s data protection watchdog has called for a unionwide one that meets its strict privacy regulations.

An already extensive digital surveillance industry going into hyperdrive with COVID-19 doesn’t surprise Ron Deibert.

“Surveillance has become so normalized into our lives and used for so many other purposes, from marketing to security, that it’s a reflex,” says Deibert, director of Citizen Lab, U of T’s elite cybersecurity watchdog group.

Deibert’s team has counted 36 proposals for tracing apps from companies, governments or academic groups. Some especially raise red flags for Deibert: none more so than Israel-based NSO Group, which sells spyware that Citizen Lab has repeatedly linked to the targetting of dissidents, journalists and activists.

The apps gaining favour in western countries are a version of the Singapore one, which uses Bluetooth technology to register close contact with other smartphones. Apple and Google announced this week they’ll ready their iPhone and Android software to host such contact tracing apps.

In Europe, a leading proponent of this type of app is a non-profit, Swiss-based group of academics called Pan-European Privacy-Preserving Proximity Tracing. It says its app will not collect geolocation history. Proximity history that is relevant to contagion — two metres is the current best guess — is stored encrypted in individual phones, inaccessible to even the phone’s user. Older proximity events no longer relevant are automatically deleted.

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If a person tests positive, health authorities provide a code to allow notifications to other smartphones whose proximity history puts its users at risk. They would then be told to self-isolate.

Such apps would only be effective if widely used. Amnesty International warns that “an increase in state surveillance powers” with such apps heightens the risk of discrimination — likely to disproportionately affect marginalized communities — while threatening privacy and freedom of association.

Deibert also warns about hacking, glitches and technical limitations that signal false contacts. He stresses that data collected in an emergency needs to be destroyed when life returns to normal.

“Once emergency measures are created and extraordinary means are pursued, they very quickly can become a new normal,” he warns. “It’s very difficult to walk them back.

In an emailed statement to the Star, the Public Health Agency of Canada said, “Mobile apps can help to encourage physical distancing by empowering Canadians to modify their activities and reduce risky behaviours.” They can complement other measures, such as regular handwashing and avoiding crowds.

“However, any support from the federal government would be highly contingent on measures taken by developers to protect the privacy and security of users,” the agency added.

Dr. Christopher Mackie, medical officer of health and CEO at Middlesex-London Health Unit, supports a mobile app with those safeguards. His unit has already developed one that helps contact tracers assess the risk level of exposure, according to criteria from Canada’s public health agency.

Tracing went as smoothly as possible when the first case appeared in London in January. The Western student in her 20s had returned from Wuhan, where her parents had COVID-19 symptoms. She had none but wore a mask while flying to Shanghai, Hong Kong, Vancouver and finally Toronto.

At Pearson, she had arranged for a taxi through a Chinese-language social media site. The driver also wore a mask. She gave him her contact details, in case he developed symptoms.

At home in London, she convinced her roommate to temporarily move out as a precaution. Her boyfriend visited wearing a mask.

She woke the day after her arrival with a slight fever and cough. She called a taxi and warned the driver, who arrived wearing a mask. She gave him her contact information, walked into emergency and was immediately isolated.

Tests from Ontario’s public health lab were negative. Two or three days later, different tests on her swabs by a lab from Canada’s public health agency came back positive.

Nurse Sheila Montague called the student all day to give her the news but got no answer. So she suited up in protective gear and knocked on the door. The jet-lagged woman had been sleeping with her phone off.

To Montague’s relief, she had self-isolated the whole time, without being advised to do so. “She was one of the smartest young ladies I’ve ever encountered,” Montague says.

“One of the things that was so frustrating for me at the time,” Mackie says, “was seeing all these prejudiced comments against Asian people and blaming the Chinese for this. And we were seeing the exact opposite — a person who went above and beyond to protect everyone, even more than we would have asked her as public health.”

Montague’s advice to the boyfriend, roommate and taxi drivers was to monitor for symptoms. She worked with hospital officials to determine if close contact occurred in the ER and found none. Passengers on her flight were considered low-risk and not contacted. Less was known at the time about asymptomatic transmission.

During two weeks of daily contacts by Montague, no one who came in close contact with the student developed COVID-19.

Montague’s contact-tracing cases quickly became more complex. The last one she finished this week required daily contact for more than a dozen people who were self-isolating.

She doesn’t only check for symptoms. She makes sure they have someone to buy them groceries; if not, she arranges for that. She advises on how an infected person can isolate from family. If a client is homeless, she’ll sometimes help search for accommodation outside of shelters.

“An important principle in public health ethics is reciprocity,” Mackie says. “If we’re asking you to stay in your home for 14 days straight there’s a responsibility on our side to make sure you have what you need.”

More than anything, Montague tries to be reassuring.

“People get quite frightened,” she says. “What I mostly do is let them talk about how they’re feeling. And I say, ‘Look at all the people who have very light symptoms. You’ll get through this.’ ”

You won’t get that from an app, Mackie says.

“The human touch can be a really powerful tool to support people and to inspire our patients,” he says. “An app really isn’t going to motivate you to self-isolate.

“So if we’re going to use an app to augment what humans already do — great. But if it’s about trying to replace them, then I think you’ve got risks on the health side of things, not just the privacy side.”