Sophie Grégoire Trudeau's coronavirus infection comes after attending U.K. event

Sophie Grégoire Trudeau has tested positive for the virus that causes COVID-19, after attending a star-studded event in London, U.K., last week with her daughter and the prime minister's mother.

Prime Minister Justin Trudeau's wife — who reported what officials call "mild flu-like symptoms" Wednesday night — was in London to attend a WE Day gathering with her daughter, Ella-Grace, and her mother-in-law, Margaret Trudeau, on March 4.

The Prime Minister's Office issued a statement late Thursday confirming she has COVID-19.

"Following medical advice, she will remain in isolation for the time being," it said. "She is feeling well, is taking all the recommended precautions and her symptoms remain mild."

The statement also said that the prime minister will remain in isolation for the planned 14 days, but will not be tested at this time because he is not exhibiting any symptoms of the illness. 

Ella-Grace and the other two Trudeau children, Xavier, 12, and Hadrien, 6, were kept home from school today as they await the results of their mother's test, the PMO confirmed.

The guest list included British celebrities like chef Jamie Oliver, actor Idris Elba, singer Leona Lewis and race car driver Lewis Hamilton. They gathered at the Wembley Arena in London with what the WE Day website says was a collection of "world-renowned speakers, A-list performers" and "thousands of young people" celebrating actions "transforming communities and changing lives."

Grégoire Trudeau was on a panel with former Australian prime minister Julia Gillard for a discussion on "educating and empowering girls and women."

An estimated 13,000 young people attended the event.

WE Day was started by Canadian philanthropists Craig and Marc Kielburger.

Grégoire Trudeau's illness was the subject of discussion in question period Thursday.

"I'm sure I speak for all members when I convey our best wishes to the PM and his wife and any other parliamentarians who have been affected by symptoms and wish her a speedy recovery," Conservative Leader Andrew Scheer said to applause from all sides of the Commons.

"Our thoughts also go out to Ms. Gregoire Trudeau and all the victims," NDP MP Peter Julian said in French. NDP Leader Jagmeet Singh has opted to stay home because he is not feeling well himself, but his doctor doesn't suspect it is a case of COVID-19.

Deputy Prime Minister Chrystia Freeland said the prime minister is self-isolating out of an abundance of caution.

"He was advised to continue his daily activities because he does not have any symptoms himself," Freeland said in French. "The prime minister decided to isolate himself and work from home until he receives the results for Ms. Grégoire Trudeau. Thank you for the well wishes."

While in the U.K., Grégoire Trudeau also visited Canada House, the building on Trafalgar Square in Central London that houses Canada's High Commission. It is not yet clear how many diplomatic staff Grégoire Trudeau met with while there.

The United Kingdom, like many other Western countries, has experienced an outbreak of the virus. As of March 11, 387 people have been confirmed as positive for COVID-19 and six patients have died.

Global Affairs Canada has not posted any advisories about travel to the United Kingdom but the U.S.-based Centers for Disease Control and Prevention (CDC) has issued a "level 2" notice warning travellers to practice "enhanced precautions" when visiting the country — one step below a warning to avoid all non-essential travel.