Hamilton's public health department says social distancing could be required until September to ensure health-care services aren't overwhelmed by COVID-19.

"The kind of social distancing that we're currently implementing is anticipated to have modest effects if its in place for four weeks," said Dr. Bart Havey, an associate medical officer of health. "It's anticipated to have noticeable and significant effects if they're in place for six months."

An infectious disease doctor also warned against getting back to normal too soon during a virtual media conference held by Hamilton's hospitals and public health on Thursday.

"If things do improve or we get some flattening of the curve, we have to be very careful about de-escalating these measures in order not to see a resurgence," said Dr. Zain Chagla, co-medical director of infection control at St. Joseph's Healthcare.

"These measures are escalating day by day and we are really in a historical situation here," he said. "The bottom line is all of us don't have a clear idea of how long these measures are going to last."

In fact, hospital leaders expect to see a further escalation of closures and other social-distancing measures.

"The situation we find ourselves in today is unprecedented," said Rob MacIsaac, CEO of Hamilton Health Sciences (HHS).

"All of us will need to adjust to this new reality," he said. "We anticipate in the coming days and weeks there will be more tough decisions to be made in dealing with this situation."

Hospitals have already started to postpone elective procedures while closing non-urgent ambulatory clinics.

"We need to act now to give ourselves the best chance to avoid a health-care disaster such as we are seeing in a number of other countries," said Dr. Michael Stacey, chief medical executive at HHS.

"We need to do everything we can to relieve the pressure on our health-care system and specifically to hospitals," he said. "We need to make some changes that, while challenging in the short term, will contain the spread of COVID-19 and safeguard our community."

The health leaders do recognize the disruption to society that the current closures create and acknowledge that might not be sustainable for months.

"The more successful we are, the longer we need to do it," said Dr. Dominik Mertz, medical director of infection control at HHS.

"I expect it will take longer than three weeks," he said. "The question is what measures continue, because I don't think that we can stay in the current state until September."

The next week will be a key indicator of how long Hamilton is likely to be living with COVID-19.

"If we let it explode, it might be done in a couple of months," said Mertz. "That's what we want to avoid."

It takes up to two weeks for COVID-19 to start showing symptoms so it's too early to know if the current social distancing is working.

"Theses are incredibly challenging times and we are all trying to come to terms with this rapidly changing environment," said Melissa Farrell, president of St. Joseph's. "It was only a short time ago that we were spectators to what was happening in China and now we are full participants."

Chagla said the importance of flattening the curve is more important than ever now that Hamilton has at least two cases which can't be traced back to international travel — meaning there is community spread.

"This also gives us time to hopefully get access to those therapeutics and vaccines in the pipeline."