LONDON (Reuters) - British Prime Minister Boris Johnson has tested positive for the 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 a 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,” he said.

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 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.

Trump, in remarks at the White House, said he spoke with Johnson on Friday to wish him a speedy recovery. “Before he even said hello he said, ‘we need ventilators,’” Trump said.

“I said, ‘wow that’s a big statement.’ Hopefully he’s going to be in good shape,” Trump said.

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

His designated deputy is foreign minister Dominic Raab. Britain does not have a publicised contingency plan in case senior ministers were incapacitated.

Britain has recorded more than 14,500 coronavirus cases and the death toll had risen to 759 as of Thursday afternoon, up by nearly a third in 24 hours. It is the seventh highest official death toll after Italy, Spain, China, Iran, the United States and France.

MODEST EARLY APPROACH

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 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.

It was unclear where Johnson was infected or how many staff and ministers would need to isolate themselves.

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.

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

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

The official guidance is for people to stand two metres (around six feet) apart to prevent contagion. This was not always adhered to for some of Johnson’s earlier news conferences.

Senior minister Michael Gove chaired Friday’s virtual conference alongside public health officials who announced plans to test health workers for the virus and the approval of two new temporary hospitals in Manchester and Birmingham.

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MEALS AT THE DOOR

Johnson will have meals delivered to the door of an apartment at 11 Downing Street, while he self-isolates.

“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.

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

Johnson’s office did not say whether the prime minister’s partner, Carrie Symonds, who is pregnant, had been tested. But Johnson’s seven-day quarantine, rather than the 14-day period for infected households, implied she was not with him as he self-isolates.

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 doors and did not come into close contact.

Queen Elizabeth, 93, last saw Johnson on March 11 and she remains in good health, Buckingham Palace said. Their regular audiences have recently conducted by telephone.

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