LONDON, ONT. -- As health professionals across the province have been warning of a surge of COVID-19 cases, wait times at London's two assessment centres are growing.

As of Thursday morning, the earliest available appointment was Monday, with most of those appointments booked up by Thursday afternoon.

Middlesex-London Health Unit Medical Officer of Health Dr. Chris Mackie said, "The numbers that we have now we know are lower than what is happening in the community because of that testing delay."

A statement issued by the Ontario Hospital Association Thursday morning called for immediate action, including a four-week lockdown in every public health unit with an infection rate of 40 per 100,000 people or higher – that's anyone in the red-control zone.

"If the lockdown approach is the best way to go, that's the way we should go, recognizing there is lots of impacts of doing that," said Dr. Adam Dukelow, Chief Medical Officer at London Health Sciences Centre.

One of the potential impacts would be on students, and whether schools should be closed.

The Thames Valley District School Board sent home a letter with students Thursday, reminding them to take all necessary materials and personal items home with them in case schools switch to remote learning in the new year.

"Now as we see the numbers continue to rise, perhaps this kind of circuit breaker approach may be advantageous. Really, our role is to be prepared for any and all eventualities, and we certainly are," said Mark Fisher, Director of Education for the Thames Valley District School Board.

Mackie says while it's possible, Middlesex-London hasn't seen the same spread within schools as other regions.

"My hope would be that if there is an extended school break, that it is done in a jurisdiction-by-jurisdiction or board-by-board basis," Mackie said.

An announcement from the province could come as early as Friday for further restrictions in the region or an all encompassing 'circuit breaker' lockdown.