TORONTO -- Labs across Canada are on the hunt for variants, and with increasing regularity, they are finding them.

The extra-contagious variants that emerged in the U.K. and South Africa have been found in seven provinces now — and Ontario recently logged the country's first case of the variant that was first detected in Brazil, known as the P.1 variant.

Over the weekend, it was detected in Toronto, Ont., making the city perhaps the first in the world to identify cases of all three current variants of concern. The patient had travelled to Canada from Brazil, and is now hospitalized.

Not only is the P.1 variant more transmissible, likely behind a deadly surge of cases and deaths in Manaus, Brazil, it also seems to infect people who have already had COVID-19.

While Ontario is set to loosen some restrictions due to lower caseloads overall, officials say they will be monitoring the situation carefully.

“While we have seen some progress, the risk remains high,” Deputy Premier Christine Elliott said Monday. “COVID-19 variants are now spreading in Ontario and remain a significant threat to controlling the pandemic in all areas of the province, including those currently with low transmission.”

Premier Doug Ford has said that the reopening process will be done carefully, and regions that have moved to the “green” classification will shut down again quickly if need be.

“[If] all of a sudden we see the U.K. variant, South African variant, Brazilian variant, go into your community — it will switch,” he said. “We’ll put the brakes on immediately, because it spreads so quickly.”

Even provinces with a just a handful of variant infections are putting out the need for caution.

“With a variant at play it will tax us beyond what we've seen, and we're really trying to take all measures possible,” Dr. Jennifer Russell, New Brunswick’s chief medical officer of health, said.

Health experts are concerned that if these variants got a better foothold in the population, they could spread faster due to their increased transmissibility, potentially leading to a surge in cases.

“All evidence suggests that they're more infectious,” Andrew McArthur, associate professor in the department of biochemistry and biomedical sciences at McMaster University, told CTV News. “So it just increases the odds, that if you're close together without personal protection, you're in a room with poor ventilation, that you have higher odds of transmitting [COVID-19]. So that increases the chance of a third wave in Ontario.”

And more variants just bring more danger.

“We know that the U.K. [variant], the South African variant, made it into Canada and now have evidence of community transmission,” McArthur said. “We're worried about the Brazilian P.1 [variant], that the same will occur.”

Scientists say the best way to fight off these variants for now is twofold: lower cases so that public health officials can focus on variants, and expand genetic testing of samples to find those infected quickly and trace and isolate their contacts.

“The key thing is we're at a very difficult part of the pandemic,” McArthur told CTV News. “The more cases and the more time go by, the more variants that occur, so these will not be the last.

“We're in a horse race between fighting these variants and overall numbers and getting to mass vaccination.”

The three variants are similar in their mutations, according to McArthur, with only minor differences between the spike proteins that allow the virus to latch onto human cells. But those differences do have an effect. With the variant that first emerged in the U.K., B.1.1.7, the main concern is its increased transmissibility, McArthur said, while the other two are thought to increase infectiousness and also potentially reduce vaccine effectiveness.

But it's a slow process to genetically test samples, taking four to seven days to decode the DNA.

“That is time consuming,” Natale Prystajecky, an environmental microbiologist with B.C. Centre for Disease Control, told CTV News. “It is about four days of full-time work, and to get that data it is very expensive.”

And with many provinces looking at lifting restrictions, it will require a delicate balance between finding and eliminating these variant infections, or else newer and even tougher lockdowns may be on the table.