Ontario Premier Doug Ford’s plans to reopen parts of the province’s economy could run into trouble, not only from his government’s struggles to expand its testing for COVID-19 but also its capacity to track those who may be infected, experts warn.
Epidemiologists say wider testing for the coronavirus that causes COVID-19 needs to go hand-in-hand with what is known as “contact tracing,” or the detective-like work that consists of public-health staff interviewing positive cases to retrace their steps and identify anyone with whom they have had close contact.
Aggressive testing and contact tracing have allowed other places, such as South Korea, to start to reopen while locking down new cases and keeping the spread of the virus in check.
But Ontario has struggled to increase its testing rate to hit its newly expanded lab capacity of 19,000 tests a day. And its current contact tracing efforts also fall far short of the levels experts say are needed before Ontarians can start to emerge from their pandemic cocoons.
“If we expand testing, then we definitely need to expand contact tracing,” said Lauren Lapointe-Shaw, a doctor and scientist with the Toronto General Hospital Research Institute who has been working with COVID-19 patients. “And ideally both need to be greatly expanded to be able to come out of this physical distancing period.”
Ontario’s goal is for local public-health units to trace 90 per cent of the contacts of anyone who tests positive with COVID-19 within one day. As of Friday, Ontario’s local public-health units were on average getting to 70 per cent of contacts within a day, said Travis Kann, director of communications for Health Minister Christine Elliott.
He said the ministry did not have a breakdown of numbers for the province’s 34 health units. He also said he expects the numbers to have increased by Monday.
Toronto Public Health, which bears the brunt of Ontario’s COVID-19 outbreak with the largest number of cases, says it is at least contacting about 70 per cent of positive cases within 24 hours to begin contact tracing.
With more than 200 new cases a day, the city’s health unit now has more than 500 staff assigned to contact tracing investigations, and counting. There are also 45 volunteer medical students working on cases. Toronto Public Health says it takes one investigator one day on average to complete contact tracing for each new case.
The agency says it aims to meet the province’s target by May 18.
Lawrence Loh, Medical Officer of Health for Peel Public Health, said the province was still working with local health units on ways to even collect the data on how close they are to hitting the contact tracing target.
“The province has just announced this objective and is working on a mechanism by which health units can collect and report on this,” Dr. Loh said.
Peel, he said, with the second-highest number of cases in the province, topped only by Toronto, was reaching 90 per cent of positive cases within 24 to 48 hours after receiving a test result. But he said his team was scaling up and planning to meet or exceed the province’s target.
Dan Flaherty, a spokesman for the Middlesex-London Health Unit, said his region has sought out most “high-risk” contacts within 24 hours, such those living or working with an infected person. However, he said in some cases there are challenges with not having enough contact information. Melissa Pinto, a spokeswoman at York Region Public Health, said the unit “attempts to make contact with all identified close contacts of a case within 24 hours.”
Hamilton Public Health says it is reaching the 90-per-cent target now.
Ian Gemmill, acting Medical Officer of Health for the Northwestern Health Unit, said his unit has met the requirement for follow-up of cases and contacts, at 100 per cent. That is because the region, which comprises 13 municipalities in Northern Ontario, has had just 16 positive cases – all of them either travel-related or close contacts or from a mining area.
Andrew Morris, medical director of antimicrobial stewardship program at the Sinai Health System and the University Health Network in Toronto, said at the moment it’s relatively easy to trace infected people’s contacts, because everyone is generally staying at home.
“But what happens when things wake up? ‘Oh, you were at the garden centre?’” he said. “When you think about how much we’ll be able to do contact tracing now, it will differ when the world opens up.”
If the province does manage to significantly ramp up its testing the difficulty in contact tracing will only multiply.
One strategy may involve using technology. Alberta has announced a smartphone app that it hopes will help with contact tracing, and Ms. Elliott, Ontario’s Health Minister, says the province is looking at similar options. Privacy watchdogs have raised concerns about the idea.
But another challenge remains ensuring that people with symptoms actually show up for tests, amid continuing confusion over who is eligible. Assessment centres in Toronto are still advising many with symptoms to stay away.
As testing and contact tracing ramps up, Dr. Lapointe-Shaw at TGHRI said it will be important to see what proportion of new cases are already on public health’s radar, because they were identified as close contacts of a previous positive case. At the moment, Ontario says 22 per cent of all cases fall into this category – with 70 per cent labelled “community transmission” or “information pending,” meaning no known link to a previous case.
“If a very large proportion of your new cases are known contact of a previous case, then that means you are really on top of the situation,” she said. “You have a really good handle on where COVID is being spread.”
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