A day after the World Health Organization officially declared the global COVID-19 outbreak a pandemic, Ontario has announced new measures to prepare for the spread of the virus in this province.

UPDATE | On Friday, Ontario announced it has confirmed 19 new COVID-19 cases

Here's what you need to know about the number of cases, new screening centres and the events impacted:

18 new cases in Ontario, including a baby

The number of COVID-19 cases jumped dramatically on Thursday morning, with health officials confirming 17 new cases in Toronto, Peel, Waterloo and Halton.

Late Thursday night, the Prime Minister's Office announced that Sophie Gregoire Trudeau, Prime Minister Justin Trudeau's wife, has tested positive for COVID-19.

The PMO says she is feeling well, is taking all the recommended precautions and her symptoms remain mild. It also says the prime minister is in good health with no symptoms.

Five of the total 59 cases have been resolved.

Health officials say one of the cases is a baby boy, who was in close contact with another patient and attended North York General Hospital in Toronto. The province says it doesn't appear that any of the cases were due to community transmission.

Among the new cases are an Oakville resident in her 40s who travelled to Colorado earlier this month and started experiencing symptoms on March 7. She went to hospital in Burlington on March 10 for testing and was confirmed to have the virus the following day. She is now in isolation at home.

The woman also recently travelled to Costa Rica, having travelled there from Toronto on WestJet Flight 2644 on March 7. She travelled back to Toronto on WestJet Flight 2643 on March 9. Passengers on those flights are asked to monitor themselves for symptoms for 14 days and report to a public health unit if they develop signs of the virus.

WATCH: Dr. David Williams says children travelling on March break increase the potential of bringing back an infection:

Chief medical officer of health Dr. David Williams says parents should think carefully before taking their children on March break. 1:25

Also confirmed Thursday is a second case of the virus in Hamilton, Ont. Few details are available about the case now but the case is not connected to a doctor who was revealed to be the city's first case Wednesday.

Two new instances of the virus were confirmed in Waterloo, Ont. The cases include a woman in her 60s, who got sick on a cruise that left Puerto Rico on March 1 and developed symptoms after returning home on March 8. She was tested in hospital and has since been released with mild symptoms.

A man in his 40s was also confirmed infected. Waterloo health officials believe he contracted the virus while visiting Las Vegas. He developed symptoms after returning home and was also released after testing.

Chief medical officer of health Dr. David Williams says parents should think carefully before taking their kids on March break. (CBC)

At an afternoon news conference on Thursday, chief medical officer of health Dr. David Williams urged parents to think carefully before taking their children on March break as this would increase the potential of bringing back an infection and introducing it into various settings, including schools and daycares.

"I'm saying that those who travel, especially when it comes to March break, if you choose to take your children with you , when you come back you're going to be asked to keep the children out of public settings, in the home setting in isolation for the 14-day period and not introduce them into the school system or into the daycare system until you complete that 14-day period," Williams said.

"The parents can continue to self monitor but if they develop symptoms, or you and your child develop symptoms and prove to be positive, then of course you will all be contacts to that case and you will be in isolation for a further 14 days until that whole situation is resolved."

Screening centres at 6 Ontario hospitals

Ontario is setting up dedicated coronavirus screening centres at six hospitals around the province in coming days, the Ministry of Health said Thursday.

"As the COVID-19 outbreak continues to evolve globally, Ontario is taking further action to ensure the province's health care system is positioned to continue to safeguard the health and well-being of Ontarians," the ministry said in a news release.

The first assessment centres will be established at the following hospitals and health facilities:

Peel Memorial Centre for Integrated Health and Wellness

The Ottawa Hospital

North York General Hospital

Mackenzie Health (in Vaughan)

Scarborough Health Network

Trillium Health Partners (Mississauga)

The centres will be located in separate spaces to protect other patients. Further screening centres will be set up in the coming weeks, the ministry adds.

The Ministry of Health has approved new physician billing codes for telephone assessments, which will allow doctors to do more evaluations that way rather than having people come into their clinics.

The province is also in the early stages of planning to establish at-home testing.

Yesterday, the Ontario government announced a $100-million contingency fund to help health authorities tackle the pandemic in the province.

Toronto activates emergency operations centre

On Thursday, the City of Toronto activated its emergency operations centre, operating at Level 2, with Fire Chief Matthew Pegg announcing a task force of about 50 people from different city agencies co-ordinating on preparations for a possible escalation of the virus. Pegg said that task force will operate around the clock.

Speaking to reporters Thursday afternoon, the city's medical officer of health Dr. Eileen de Villa said anyone returning from travel is urged to avoid public or group gatherings, and to monitor themselves for symptoms. She did not discourage people from travelling over the March Break, however.

Event organizers are also urged to consider whether they can postpone or hold their events virtually, but the city has not implemented any sort of ban. De Villa is encouraging people to avoid shaking hands.

"Bans are fairly blunt instruments," said de Villa, insisting the best measures for protection remain personal hygiene including hand washing.

Upcoming jury trials suspended

On Thursday night, the Ontario Superior Court of Justice announced that upcoming jury trials in the province have been suspended due to COVID-19.

"Ontario Superior Court of Justice has suspended jury selection for future trials at this time. Jury panels for upcoming matters are being directed not to attend court," the court said on Twitter.

Ontario Superior Court of Justice <a href="https://twitter.com/SCJOntario_en?ref_src=twsrc%5Etfw">@SCJOntario_en</a> has suspended jury selection for future trials at this time. Jury panels for upcoming matters are being directed not to attend court. Jury trials currently in progress will continue, unless the trial judge orders otherwise. —@SCJOntario_en

St. Patrick's Day Parade cancelled

Organizers of Toronto's annual St. Patrick's Day Parade, scheduled for Sunday, March 15, have decided to cancel this year's parade in light of the virus.

"We're dealing with a serious health issue globally and I think we've got to do our part and contain this as best as possible," said Shaun Ruddy.

This is the first time in 33 years that the parade has been cancelled, Ruddy said.

"We're really disappointed and for obvious reasons we wish we could have the parade but the climate just doesn't allow that," he said, adding it "will be back bigger, better and stronger than ever next year."

Are you concerned you may have COVID-19? It's important to know the symptoms before seeking medical attention. Here's a guide from the World Health Organization: