TORONTO -- Eighteen more cases of the novel coronavirus (COVID-19) have been confirmed in Ontario, bringing the provincial total to 60, including five recoveries. 

The new cases include a baby boy and the Canadian Prime Minister's wife Sophie Gregoire Trudeau.

The Prime Minister's Office confirmed that Gregoire Trudeau tested positive for COVID-19 on Thursday after exhibiting flu-like symptoms after returning from the United Kingdom. She will remain in self-isolation for 14 days.

Meanwhile, the child was in close contact with another patient and attended North York General Hospital in Toronto, health officials said.

The other new patients are in regions across southern Ontario, including Toronto, Peel, Waterloo and Muskoka, and all have been released into self-isolation.

READ MORE: This is what we know about each confirmed COVID-19 case in Ontario

Some of the patients have a travel history to Puerto Rico, Italy, Costa Rica, United States and Spain. 

The travel history for two of the patients is currently pending, health officials say. Four of the patients contracted the virus through close contact. 

Speaking to reporters, Associate Chief Medical Officer of Health Dr. Barbara Yaffe said that seven of the 18 cases confirmed Thursday had recently travelled to the United States.

“That’s something of a trend we are seeing,” she said.

The province says it has tested more than 4,100 people for the virus so far, and the vast majority of the tests have come back negative.

Due to the increase of patients diagnosed with the virus in a 24-hour period, health officials are urging anyone who travels to avoid public gatherings and not to visit vulnerable populations such as seniors.

The pandemic has also caused a number of events to be cancelled or suspended its operations, including a number of major sport leagues. Ontario’s Chief Medical Officer of Health commended the organizations for making the difficult decision.

“If you have gatherings of over 1,000, I would prefer that you did not hold those events, that you would postpone or delay those,” Dr. David Williams said. “If you have gatherings of between 250 and 1,000 … consult with your local public health.”

MORE: Here’s what’s cancelled and closed amid COVID-19 concerns

Meanwhile, Members of Provincial Parliament at Queen’s Park unanimously passed a motion that would allow them to avoid returning to the legislature if the COVID-19 outbreak worsens.

While MPPs are set to return on March 23, the motion gives Government House Leader Paul Calandra power to notify the speaker the legislature will not reconvene.

The Progressive Conservative government is set to table its budget March 25.

"It is our goal, obviously, to present a budget in the legislature and I think that is very important to us," Calandra said. "I think that's the place where it should happen."

Hours later, Education Minister Stephen Lecce announced that publicly-funded schools would be closed for two weeks after March break due recent developments “both internationally and at home.”

Schools are scheduled to remain closed from March 14 to April 5. After the two week period, the government will re-evaluate the situation and decide if further action is needed.

The government also announced that dedicated assessment centres will open in the next few days at William Osler Health System's Peel Memorial site, The Ottawa Hospital, North York General Hospital, Mackenzie Health in York Region, Scarborough Health Network and Trillium Health Partners.

The World Health Organization declared the coronavirus a pandemic on Wednesday. 

With files from The Canadian Press