British Prime Minister Boris Johnson has tested positive for coronavirus and is self-isolating at his Downing Street residence but said he would still lead the government’s response to the accelerating outbreak.

Johnson, 55, experienced mild symptoms on Thursday, a day after he answered questions at the prime minister’s weekly question-and-answer session in parliament’s House of Commons chamber. He received the positive test result at around midnight.

“I’ve taken a test. That has come out positive,” Johnson said on Friday in a video statement broadcast on Twitter. “I’ve developed mild symptoms of the coronavirus. That’s to say – a temperature and a persistent cough.

“Be in no doubt that I can continue, thanks to the wizardry of modern technology, to communicate with all my top team to lead the national fightback against coronavirus.”

Health minister Matt Hancock, another senior member of the British government’s response, said he had also tested positive and was self-isolating at home with mild symptoms. The government’s top medical adviser also said he had symptoms.

Johnson is the first leader of a major power to announce a positive test result for coronavirus. Canadian Prime Minister Justin Trudeau went into isolation earlier this month after his wife tested positive for the virus.

U.S. President Donald Trump and German Chancellor Angela Merkel have both been tested, so far with negative results.

Johnson chaired a government meeting on the coronavirus on Friday morning via teleconference.

His designated deputy is foreign minister Dominic Raab. It was not immediately clear what the contingency plan was if senior ministers were incapacitated.

Britain has recorded more than 14,500 cases of the illness and the death toll shot up to 759 as of Thursday afternoon, up by nearly a third in 24 hours. This is the seventh highest official death toll in the world after Italy, Spain, China, Iran, the United States and France.Britain’s Prime Minister Boris Johnson applauds outside 10 Downing Street during the Clap For Our Carers campaign in support of the NHS, as the spread of the coronavirus disease (COVID-19) continues, London, Britain, March 26, 2020. Pictre taken March 26, 2020. REUTERS/Hannah McKay

The coronavirus is the worst global health crisis since the 1918 influenza epidemic. Britain, which has the world’s fifth largest economy, initially took an approach to containing the spread of the disease that was modest in comparison to European countries such as Italy.

But Johnson changed tack and imposed stringent controls after projections showed a quarter of a million people could die. On Monday he banned Britons from leaving their homes for all non-essential reasons, effectively shutting down large parts of the economy.

Now he is in isolation too.

“I am working from home. I’m self-isolating,” Johnson said.

It was unclear where he was infected or how staff and ministers would need to isolate themselves after dozens of daily meetings, including news conferences, in Downing Street.

Johnson last appeared at a news conference on Wednesday, flanked by the government’s chief scientific adviser, Patrick Vallance, and England’s Chief Medical Officer, Chris Whitty. The event was closed, with journalists asking questions by video link.

A spokesman said that the moment Johnson felt symptoms he took steps to avoid close contact, adding that ministers would need to self-isolate if they developed symptoms.

Whitty said on Friday he was experiencing symptoms and would also self-isolate.

The official guidance is for people to stand two meters (around six feet) apart to prevent contagion. This was not always adhered to for some of Johnson’s earlier press conferences, when he appeared with other top officials, although the distance between lecterns had been increased by Wednesday.

Johnson will have his meals delivered to the door of an apartment at Number 11 Downing Street, while he self-isolates for seven days from the warren of corridors and rooms that make up the seat of British political power at Number 10 Downing Street.

“The doors between Number 10 and Number 11 have been closed off to all other staff who work in the building,” a Downing Street spokesman said. “The PM will work from the office and the study in Number 11.”

His finance minister, Rishi Sunak, who traditionally works out of Number 11, is not self-isolating, a Treasury source said.

Johnson’s office would not say if his 32-year-old partner, Carrie Symonds, who is pregnant, had been tested. However Johnson’s seven-day quarantine, rather than a lengthier 14-day period for infected households, implied she was not currently living with him.

Britons paid tribute to health workers on Thursday evening by clapping and cheering from doorways. Johnson and Sunak took part, but came out of separate entrances on Downing Street and did not come into close contact.

Queen Elizabeth last saw Johnson on March 11 and she remains in good health, Buckingham Palace said. The 93-year-old monarch usually sees the prime minister once a week but has recently conducted the regular audience by telephone.

Prince Charles, the 71-year-old heir to the British throne, tested positive for coronavirus earlier this week. He is in good health and is now self-isolating at his residence in Scotland with mild symptoms.

Reuters