Here's how health officials determine whether they should announce a COVID-19 outbreak

Since B.C. entered Phase 2 of its gradual reopening in mid-May, notices have gone out about various locations where people may have been exposed to COVID-19.

Provincial Health Officer Dr. Bonnie Henry said on Wednesday that 70 cases have now been linked to events and parties in the Kelowna area over the past several weeks. And over 1,000 people in B.C. are currently self-isolating for two weeks, having been warned that they may have come into contact with someone with COVID-19 as a result of those gatherings.

But you won't necessarily get a phone call from public health officials, or see news posted of an outbreak at a location that you've recently visited.

Henry explained during her daily briefing on Wednesday that warnings depend on the scenario in which there may have been exposure.

"It depends a little bit about where the setting is that it's happened, how many people have been exposed, what type of exposure it is, and whether we are able to to effectively find people who may have been at risk," she said.

Risk to the public a determining factor

Outbreaks in settings with potential for widespread exposure — including health-care settings, long-term care homes, and schools — are officially announced in B.C.'s COVID-19 briefings, led by Henry and Health Minister Adrian Dix.

In settings other than the three listed above, an outbreak will only be declared if it's determined there is a risk to the public.

That means if contact tracers are confident they've contacted everyone who might have been exposed, or if the exposure is determined to be low-risk, they won't necessarily issue a public notice.

But if contact tracers aren't able to contact everyone, they'll declare an outbreak — like those recently declared at a number of restaurants and nightclubs in Vancouver. Henry said in those cases, it was impossible to ensure that everyone who might have been in those locations had been contacted — though restaurants are now mandated to take down contact information for everyone who visits. 

"That's for two things — one, so we can find people quickly and that we can find everybody who was there," said Henry.

"It's in our best interest to give the restaurant our name and phone number, so that if there was somebody there who was sick and put us at risk, then we can be contacted quickly so we know what to do and we can protect those that are closest to us as well."

Henry said in some cases, businesses have issued notices about outbreaks to be proactive and transparent with their customer base — without public health requiring them to do so.

"It's essential, if we direct them to do it, but they're able to do it as a way of just reassuring their customers and the people that work in the facility that the right measures have been taken. So there's a bit of a balance there," she said.

Other alerts, like potential exposure on flights, buses, work sites, and more, can be found on the B.C. Centre for Disease Control's website.