Beijing Olympics' top doctor defends stricter COVID testing as necessary protection

The chair of the Beijing 2022 medical expert panel is defending the strict protocols in place for participants attending the Olympics in China as necessary to reduce the risk of spread during the Games.

Dr. Brian McCloskey told CBC Sports on Friday that the protocols have detected more positive cases in arrivals to Beijing than at a similar point for the Tokyo Olympics in July, something he said is expected and what they are designed to do.

"It's picking up people who might be infectious and might get into the [Athletes] Village and cause a problem," he said. "And now, we're having to work out how we deal with those cases and get as many people as possible into the Games, and as many people as we can safely."

The Olympics are scheduled to officially open on Feb. 4.

The Beijing Olympic Committee has set a higher threshold for sensitivity on COVID-19 testing compared to the number being used by Canadian health standards. The cycle threshold (Ct) value being used in China to detect an infection is 40, compared to 35 in many places in Canada. The higher the Ct value, the less infectious is a person with COVID-19. 

Dr. McCloskey said the threshold number used for these Games was made in partnership between the IOC and Beijing Olympic Committee based on conversations over many months and building on what officials learned in Tokyo. 

"There are obviously differences in the way every country handles coronavirus. So we've been evolving it. Even in the last week, we've been exchanging scientific papers with our colleagues in China to make sure we understand the evidence behind how the testing gets done," McCloskey said. 

"We are using a standard PCR test, which is an international standard the World Health Organization approved. Every laboratory sets its own standards in terms of Ct values, but these are consistent across the world."

Any athlete or Games participant who has tested positive within the last 30 days is in a precarious situation with this higher threshold, however. Participants are required to provide five negative PCR tests before they're allowed to fly to China.

If a person does test positive on arrival, they will be isolated until they can produce two negative test results.

WATCH l China's COVID-19 testing threshold may prevent athletes from competing:

If there is ambiguity in the results — for instance, two negatives and then a positive — a 20-person panel of medical experts will make an evaluation of infectiousness based on the CT values, vaccination history and other factors.

The panel includes representation from the China Centre for Disease Control, the Beijing CDC, and five international representatives of the IOC, the International Paralympic Committee and Winter International Federations.

"We try to make that very fine judgment based on the best science we can find. But none of this science is absolutely clear, because we don't know that much about coronavirus yet," Dr. McCloskey said.