Physical distancing has halved spread of COVID-19 in B.C., official modelling suggests

Health officials say physical distancing restrictions in B.C. are successfully beginning to slow the rate of spread of new COVID-19 cases in the province, perhaps by as much as half.

But despite the «glimmer of hope,» provincial health officer Dr. Bonnie Henry and other officials stressed that the province is not out of the woods and the health-care system still needs to be prepared for an inevitable surge in hospitalizations.

«I’m trying not to over-call it, but I do believe we’ve seen a flattening, a falling-off of that curve,» Henry said Friday, referring to the growth of new COVID-19 patients in B.C.

«What we need, though, is for everybody to continue to pay attention to these [physical distancing] measures so we can continue to prevent transmissions in our communities … for the coming weeks.»

The hopeful news came as part of a report released Friday, which found that the province’s health-care system is «reasonably» prepared to handle a surge in critical care cases related to COVID-19 if the flatter trajectory continues.

The report said 17 of the biggest hospitals in B.C. have now been identified as primary COVID-19 treatment sites.

Officials say those hospitals are ready to meet demand, even if the local outbreak were to mimic the severe scenario seen in China’s Hubei province.

If the situation in B.C. deteriorated to the point where the 17 hospitals could not keep up, as was the experience in Italy, the province said additional centres are being prepared to care for the overflow.

Watch: Dr. Bonnie Henry outlines the modelling B.C. is using to make predictions around hospital capacity:

Provincial health officer Dr. Bonnie Henry says B.C. modelling shows that while the spread of COVID-19 appears to be slowing, the next two weeks are critical.1:20

Compared to China, northern Italy

A number of health-care officials compared the estimated trajectory of new cases in B.C. with the case growth previously seen in two of the most severe coronavirus outbreaks: in northern Italy and China’s Hubei province.

Both regions have been epicentres of the pandemic, with tens of thousands of cases and hospitalizations.

Taking those two regions’ experiences as examples of worst-case scenarios, B.C. looked at its own health-care system to determine whether the province has enough beds and ventilators in case it goes down a similar path.

Henry said the data is for planning purposes, cautioning that it is not a prediction.

‘Cascading’ approach

B.C. said there is a likely scenario of the province’s outbreak ending up below or at the same level seen in the Hubei province, where the pandemic originated in the city of Wuhan.

The report found the 17 provincial hospitals identified as primary care centres would be prepared enough to handle that kind of outbreak. They are the biggest hospitals across all of B.C.’s health authorities, with the highest level of expertise and capacity for critical care.

B.C. Health Minister Adrian Dix points to a modelling graph showing different COVID-19 scenarios on March 27, 2020.(Mike McArthur/CBC)

A briefing offered Friday, however, said that network would be overwhelmed if B.C.’s outbreak reached a level like northern Italy’s. Provincial Health Minister Adrian Dix said B.C. is developing a «cascading» approach to free up additional hospital beds in case that happens, though it is not looking likely based on Friday’s modelling.

The province believes it should have enough ventilators to meet demand, even if it follows Italy’s extreme pattern, assuming 80 per cent of patients in intensive care units (ICU) need to use them.

Dix said there are at least 1,272 ventilators in the province, with more on order.

The report found the most populated areas of the province are better equipped for a bigger outbreak, with Northern Health seeing the lowest amount of ventilators. It also said Interior Health and Island Health will have higher percentage of critical care hospitalizations because their populations are generally older.

Restrictive measures working, province believes

The province believes restrictive measures around travel, large gatherings and physical distancing introduced between March 12 and 16 are saving B.C. from an outbreak scenario like China’s or Italy’s.

Without those measures, officials believe B.C. would be seeing a 24 per cent daily increase in cases — or 215 new cases per million people, every day.

Instead, the report said, B.C. has only seen a 12 per cent daily increase since physical distancing began, or about 130 new cases per million people.

That growth rate is lower than those of northernItaly and the Hubei province.

Officials cautioned B.C. could still see a spike, if an outbreak happened in a remote community or a vulnerable care home.

Henry has also warned the 14-day incubation period is not over for people who were infected with the novel coronavirus before the restrictions began. She said it will be at least another week before we see the full effects of physical distancing.

B.C. has proactively freed up more than 3,900 hospital beds by deferring non-essential surgeries, something that didn’t happen in overwhelmed countries like Italy.

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