REGINA -- An epidemiologist at Ryerson University says testing needs to be a top priority as the province of Saskatchewan re-opens its economy next month.

Tim Sly calls COVID-19 a “stealth virus,” since as many as half of the people infected by the virus may never show any symptoms.

“They used to say in real estate, location, location, location,” he told CTV News Thursday. “Here, it’s going to be testing, testing, testing.”

Premier Scott Moe unveiled the province’s plan to re-open the economy on Thursday morning. The first phase of five is scheduled to begin on May 4.

Moe highlighted the importance of testing in his plan. Saskatchewan has the second-highest testing rate per capita in the country.

Sly said testing should focus on people who may expose Saskatchewan’s most vulnerable residents to the virus.

“The old folks homes, the long-term care homes, everybody in those places right down the gardener and the janitor should be tested for the virus,” he said.

Sly says no matter what, cases will increase as Saskatchewan lifts its restrictions.

“You can’t stop it, as long as there’s a virus out there and as long as there’s fuel,” he said.

He added there should be careful consideration of who can return to their normality and precautions in place.

“We hope to see buildings sites with lots of hand washing stations, people wearing N95 masks,” Sly said.

According to Sly, the only way to completely stop the spread of the virus is to keep “everybody locked down until we have a vaccine.” But, he said he realizes that’s not the ideal answer.

“These are human beings and we’re all in it together,” he said.

He says cases will likely see an exponential increase within eight or nine days of relaxing restrictions. Therefore, Sly says, it’s important to be careful and work to keep at-risk people safe.

“Perhaps we can crack open the door a little bit, selected people under certain conditions,” he said. “Keep the case numbers down nice and low.”

With files from CTV News' Jill Machyshon