Modelling shows public health restrictions work, says Yukon's top doctor

Yukon's chief medical officer on Tuesday touted the territory's response to the COVID-19 pandemic, saying that modelling shows how things could have been much worse without public health restrictions.

Dr. Brendan Hanley spent most of his regular Tuesday news briefing explaining how officials have been analyzing the effectiveness of public health measures, to help guide future decisions about easing restrictions.

"We know they're effective, we've shown they're effective, the modelling data shows us the effectiveness of public health measures," Hanley said. 

To date, Yukon has seen 11 confirmed cases of COVID-19 and all of those people have recovered from their illness. The last confirmed cases were announced more than a month ago.

Using slides and graphs, Hanley showed how things might have evolved if the territory imposed no restrictions, or if the territory waited for a couple of weeks after the first confirmed case arrived in Yukon.

Watch Tuesday's news conference here:

With no restrictions, he explained, one case arriving in Yukon could have resulted in nearly 2,000 cumulative cases within two months. That would have seen an estimated 77 people in hospital at the two-month mark, and about 23 of those people in intensive care.

That's based on an assumption that any one infected person would infect an additional 2.4 people, on average. Under that scenario, there may have been more than 6,400 active cases of COVID-19 in Yukon within about 100 days.

"So, clearly enough to be more than what our health care system could contain," he said.

A second scenario involved the introduction of public health restrictions two weeks after the first confirmed case. In that scenario, there would have been an estimated 67 cumulative cases within two months.

"So you can see that even if we had a lag time between introduction and implementation of public health measures, it still would have had a profound effect on reducing, by about a hundredfold, the number of infections," he said.

As it was, Yukon declared a public health emergency and started to impose restrictions — such as mandatory 14-day isolation or people arriving in Yukon —  before there was a single confirmed case in the territory. Hanley called it "the best scenario in terms of disease transmission." 

Easing restrictions

Hanley said the modelling does not allow officials to assess the impact of any individual public health measure, but rather look at the whole package.

He says they're now working on building more sophisticated models to guide decisions around easing restrictions, including loosening up the border sometime down the road. 

"We're looking for models that are more realistic to what our actual situation is. So we're partnering with the Public Health Agency of Canada to run various models with different degrees of public health measure relaxation," Hanley said.

On Wednesday, personal care establishments such as hair salons and tattoo parlours will be allowed to reopen under new guidelines and with a government-approved plan. Eat-in restaurants can open on Friday, also under new guidelines and with an approved plan.

The territory's full reopening plan was presented earlier this month, but includes few solid dates. Rather, health officials have said things will be eased gradually, as certain benchmarks are met.

Hanley said so far the modelling has clearly shown that "public health measures matter."

"No matter what we do, until we get to a point where we are confident that we have no more risk of COVID[-19] introduction into the territory, we have to rely on the package of public health measures."