What’s holding Toronto back from reopening?
The ‘reproduction number’ is key to policy on containing virus
As areas across Ontario prepare to enter the second stage of reopening this Friday as new COVID-19 cases drop, Toronto will not be joining them, with most new cases of the virus happening in the GTA.
That’s what new data from the province and city show, and that’s likely one of the reasons why Toronto, as well as Mississauga and Brampton, is not joining the seven regions slated to start revving up their economies at the end of this week.
Dr. Eileen De Villa, Toronto’s medical officer of health, said she believes the province’s decision to delay the city’s reopening was “reasonable given our current circumstances,” adding “at this time, I cannot give you an exact date for us to move to the next stage of reopening.”
The overwhelming majority of Ontario’s new infections continue to occur in the GTA;149 of the 211 cases reported on Monday came in the region’s five health units. But the rate of new cases is also falling sharply in the Toronto area.
On Monday, Toronto Public Health reported fewer than 100 new cases for the fourth straight day. Before that streak, 65 of 66 consecutive days had seen more than 100 reported infections.
Since last Monday, the city has seen an average of just102 cases per day, the lowest for any seven-day period since April 7, a time when the rate of new infections was still growing rapidly ahead of the first peak in cases in the city. That came about two weeks later on April 23, when the same seven-day average hit 209 cases per day.
To date in Ontario, there have been 34,231(up 211from the day before) positive cases of COVID-19 reported since the pandemic began, and 2,582 deaths (11 more than the day before).
Ris the loneliest number
Toronto’s current reproduction number, known as R, is the lowest it’s been since the pandemic began — 0.65 as of Monday — but as many other areas move forward, the city will remain in Stage 1.
The R number refers to the average number of secondary infections from one case of COVID-19. If it’s below one, the infection will die out eventually, says Chris Bauch, a mathematician with the University of Waterloo. When R is above one, infections continue to grow.
“We can never prevent all secondary infections from happening,” says Bauch. “But we can ensure that each person infects less than one more person on average. If we can accomplish that, the infection will die out.”
Toronto Public Health is monitoring the R number and Dr. Vinita Dubey, Toronto’s associate medical officer of health says in an email that “Prior to implementing our strict public health measures in mid-March, each new case of COVID-19 in Toronto went on to infect an average of just over 3 other people.”
Bauch says the R number can change very quickly, but the provincial guidelines are based on longer trends over two to four weeks, so to meet reopening standards the city must “maintain a lower R value over time.”
Highest in province
At 1.71, the Windsor-Essex health unit has the highest current R number in the province. The area is battling an outbreak in farm workers — the third time it has had cases escalate in a specific population, after waves in cross-border healthcare workers and long-term care homes.
Cases on farms have multiplied in recent weeks, said Dr. Wajid Ahmed, the area’s medical officer of health, who said 80 to 90 per cent of cases are happening in agriculture. The virus spreads easily there because of shared accommodation among the 8,000 to 10,000 temporary foreign workers at Windsor-Essex farms.
In February, the health unit created resources, tools and information to prevent “this from happening in the first place,” said Ahmed, but workers have been hesitant to come forward or see a doctor when they are feeling ill.
Another complication is that workers who have the virus are isolated in hotels in the area and hotels are nearing capacity.
“If the hotels and everything are full, and we cannot safely isolate these people, what are we going to do about the isolation protocol?” said Ahmed.
Cottage country
The Simcoe-Muskoka health unit has a current R number of 1.22. Dr. Charles Gardner, the area’s medical officer of health, said it has typically been below one since late April, but there has been a recent uptick in cases.
Institutional outbreaks have declined, says Gardner, but infections are occurring among close-contact and communityacquired cases, which means the source of the infection can’t be identified. Simcoe-Muskoka’s cases have mostly been in the southern part of the unit — Barrie, Bradford West Gwillimbury, New Tecumseth and Innisfil — not Muskoka.
Didn’t make the cut
In Peel, the current R number is 0.65, which Peel Public Health says is “good.”. But the province announced on Monday that the region would have to wait to move to Stage 2.
“We know that over the past few weeks across Peel, up to 50 per cent of our cases are household contacts and there are others that are related to workplace investigations,” said a spokesperson for the health unit. “Currently, very few cases are linked to outbreaks in longterm care facilities.”
Halton gets green light
Halton’s current R is higher than Toronto’s at 1.2 but the province gave the region the nod on Monday to move to Stage 2.
In a letter last week to Premier Doug Ford, Halton’s regional chair and four local mayors outlined why Halton had made the cut. The letter noted among other things that the region had no institutional outbreaks, that local hospitals were sustaining adequate capacity, and that 90 per cent of new COVID-19 contacts were being reached by regional public health within one day.
Niagara lowers R
The region faced a recent outbreak on a farm where the virus spread to 57 people over two days after infected workers didn’t report symptoms early enough. Testing controlled it and the health unit is back to its baseline, which has been new cases in the single digits on most days, says Dr. Mustafa Hirji, acting medical officer of health for the region.
Niagara now has one of the lowest R numbers in the province: 0.29.
Hirji says with a Stage 2 reopening on the horizon, the spread of the virus will depend on whether residents continue to practice preventative measures such as physical distancing and frequent handwashing.