Ontario had gone 7 straight days with fewer than 100 COVID-19 cases. Now what?

Ontario marked a significant achievement in its COVID-19 fight this past week. In each of the last seven days,the province has recorded fewer than 100 cases of the novel coronavirus.

• UPDATE: On Monday, the province's streak ended when it announced there are 115 new COVID-19 cases across the province. You can read more about the latest cases here.

While this may be seen as cause for celebration, medical expertssay people should not forget that COVID-19 is still very much around.

"Complacency is something we'll always have to worry about and make sure that people realize that COVID's still there," infectious diseases physician at Trillium Health Partners in Mississauga, Dr. Sumon Chakrabarti told CBC News.

"The big vulnerability is the fact that there are so many people here [in Toronto] and there are so many more chances of having lapses in an indoor environment with lots of people."

Chakrabarti said with bars, restaurants and gyms now open, people are more likely to be grouped together, thus increasing the risk of outbreaks.

"I do expect to see spikes in the numbers, that doesn't surprise me, but the fact that the overall trend has continued to drop is very, very good," Chakrabarti said.

"Places like Toronto, places like the GTHA, we've been in Stage 3 for less time and obviously the eyes are upon us right now because it's such a more densely populated area.

"We've got to keep a close eye on this and if the trend starts to go upwards, we may have to pull back and put in some public health restrictions," Chakrabartiadded.

We are just as susceptible as a population to this infection as we were in the beginning.- Dr. Sean Blaine

Like Chakrabarti, Stratford-based family physician Sean Blaine said, while the numbers are encouraging, Ontario residents should not be lulled into complacency.

He said every part of the province remains at high risk and whether or not new outbreaks occur will depend on how people chooseto conduct themselves.

"We know that the nature of this particular virus is that it continues to circulate in all of our communities among people who have no idea that they're actually infected, have no idea that they could be passing it on to other people, and it does this very, very quietly," Blaine told CBC News.

"It would be easy to conclude from the lower case numbers that the virus is gone when in fact the threat remains there.

"In fact, we are just as susceptible as a population to this infection as we were in the beginning," Blaine added.

If everyone remains confined to their bubble of 10 people, and use all of the protective measures that are known to work,the province could sail through the fall and winter until next year, when hopefully a vaccine comes along, the physician said.

"But that's not going to happen, because unfortunately there are going to be those among us who choose to have closer interactions with people beyond the 10 exclusive people that you're supposed to have in your bubble," Blaine said.

Ontario Health Minister Christine Elliott announced the full week ofnumbers below 100 in a tweet.

"It's official: for a full week, Ontario has now reported fewer than 100 cases, with 79 cases of #COVID19 today, a 0.2% increase," Elliot said Sunday.

Enhanced public health measures essential to COVID-19 control

Meanwhile, to control the spread of COVID-19 as Canada reopens, enhanced testing to identify and isolate cases, contact tracing and quarantining combined with physical distancing are essential, according to a new modelling study published Monday in the Canadian Medical Association Journal.

According to the study, school closures will help but won't be sufficient to control the epidemic if community transmission persists.

It adds that partial closures of workplaces and general community closures would have a greater effect because transmission outside of the household is occurring primarily in these settings.

"When we have high levels of community transmission combined with minimal public health interventions and low adherence to physical distancing, school closures will have a minimal impact in combination with these interventions and will not be sufficient to control the epidemic," said Dr. Victoria Ng from the Public Health Agency of Canada.

"In contrast, workplace and general community closures were much more effective, because transmission outside of the household is occurring predominantly in these settings.

"The model findings are consistent with our observed experience in Canada where restrictive closures over the last few months have been effective in keeping our health-care system from being overwhelmed, but this has had a negative impact on our economy and health effects on society," added Ng.

Consistent with other studies, the researchers found that approximately 0.25 per cent to 56 per cent of Canadians could become infected over the course of the pandemic depending on the level of public health intervention implemented in the coming months and years.

Get the COVIDAlert app

Meanwhile, Dr. Blaine is urging all Ontario residents to get the province's COVID Alert app.

Theapp can tell userswhether they have been near someone who has tested positive for COVID-19 over the previous two weeks.

"I think it would be great ifas many people as possible would download the app," Blaine told CBC News.

"It's just another tool in our repertoire when it comes to rapidly doing contact tracing."

COVID Alert is the federal government's latest move in the battle to prevent the spread of COVID-19 as Canada's economy gradually reopens. Here's how it works:

• You start by downloading the app to your smartphone.
• That will allow the phone to use Bluetooth technology to exchange signals with nearby phones.
• If someone tests positive for COVID, their public health authority will give them a one-time key to enter intothe app.
• The app will then send out notices to every phone that has been within two metres of the infected person'sphone for at least 15 minutes over the previous 14 days as long as those other phones alsocarrythe app.
• Those who receive a notification will receive instructions on what to do next.