CALGARY -- The men's world curling championship in Calgary remained in a holding pattern Saturday just short of its finish line because of positive tests for the COVID-19 virus.

Four members of three international, non-playoff teams tested positive for the virus in “exit” tests before departing Canada. They did not show symptoms of the coronavirus.

A playoff game and a pair of semifinals were called off Saturday. The world championship is scheduled to conclude Sunday with the gold and bronze-medal games.

Four additional teams were in close contact with the infected individuals.

The World Curling Federation and Curling Canada awaited tests conducted on the remaining five playoff teams Saturday to determine if the championship could resume at WinSport's Markin MacPhail Centre.

“We're trying to get this done,” said Scott Arnold, the WCF's head of development.

“We're doing everything in our power to do that, but we have to wait for the testing to see if we actually have that available to us.”

Athletes and team personnel were quarantined in their hotel rooms Saturday.

Shortly after Canada's Brendan Bottcher was eliminated from contention by Scotland on Friday night, the WCF announced infections had been detected among participants and suspended the competition.

“Obviously gutted,” said Nolan Thiessen, Curling Canada's director of broadcast, marketing, innovation, event presentation and athlete liaison.

“Friends, colleagues, teammates, our broadcast partners, just completely gutted, but we're going to figure it out, figure out what happened and see if we can still compete the season.

“Health and safety comes first and we'll figure out the championship side of it later.”

Alberta Health and the Public Health Agency of Canada approved Curling Canada's plan to host events in a controlled environment walled off from the general public.

The men's world championship was the fourth event in Calgary's curling bubble after the Canadian men's, women's and mixed curling championships, in which there were no reported cases of COVID-19.

It's not yet known if the positive cases at the world championships involve a variant of the virus, said Dr. Bob McCormack, who is the chief medical officer for the curling hub.

Curling Canada adopted many elements from Hockey Canada's operation of the world junior men's hockey championship in Edmonton from Dec. 25 to Jan. 5.

The international curling teams didn't arrive in Canada by charter flights as the hockey players did, but flew commercially.

A negative test taken less than 72 hours before travelling to Calgary was required.

Upon arrival in Calgary, the athletes and team personnel began a week-long “managed quarantine protocol” with four separate tests taken during that span before curlers were cleared to compete.

All 14 teams, including 13 from other countries, started the men's world championship April 2.

Teams are confined to the arena and their hotel across the Trans-Canada Highway, and drive themselves back and forth.

Masks are mandatory outside hotel rooms and off the field of play, and hand sanitizer was readily available, yet the pernicious coronavirus infiltrated the curling bubble.

“We're actually assessing that as we speak,” Thiessen said. “That's part of the contact-tracing process. We're trying to figure out not only where the spread is, but where this could have happened.”

The WCF's preference is to finish the event Sunday. Pushing it into next week is a logistical nightmare for broadcast and property reasons.

A pair of Grand Slams, which are Rogers Sportsnet properties and not Curling Canada's, are scheduled to start Wednesday in Calgary.

The Humpty's Championship Cup will be followed April 20-25 by the Princess Auto Players' Championship.

Those tournaments feature Canadian and international men's and women's teams, including four that are competing in the men's championship.

Athletes not in the world championship are arriving to undergo their testing and quarantine protocols for the Grand Slams, but aren't mixing with the world championship teams.

“Those athletes are at a different site completing their entrance protocols for Grand Slams,” said Dr. Danielle Kelton, the on-site medical officer in Calgary.

“We are in communication with them and they're not in direct contact with any athletes currently in the bubble.”

The women's world curling championship, relocated from Switzerland to Calgary, follows April 30 to May 9.

McCormack believes a virus-free curling bubble can be restored for upcoming events.

“There's unknowns we need to sort out, but I am confident it will resume,” he said.

“Even though we've had a problem with the men's worlds, we have the opportunity to re-establish a clean bubble same as the Tournament of Hearts, which was different from the Brier, which was different from the mixed Canadian championship, which was different from the worlds.

“They're separate events, so I'm hopeful not only will we be able to finish this event - that's a moving target - but we'll be able to establish a new bubble for the next events that are safe.”

This report by The Canadian Press was first published April 10, 2021.