Boris Johnson
(Photo : Reuters/Pippa Fowles)
Prime Minister Boris Johnson thanks the NHS in a video message on Easter Sunday, in 10 Downing Street, London, Britain, April 12, 2020.

U.K. Prime Minister Boris Johnson has tested negative for COVID-19, according to his spokesperson, James Slack on Monday, one day after he was discharged from the hospital.

Slack said he is "not immediately returning to work," stating that Johnson had spoken to Foreign Secretary Dominic Raab, who has been substituting during the prime minister's illness, over the weekend.

Johnson was admitted to the hospital for a week with the novel coronavirus, with symptoms of a fever and cough, including four days in the ICU between Monday and Thursday before he was released from St. Thomas' Hospital in London.

The 55-year-old British prime minister was discharged Sunday and will continue his period of recovery at Chequers, his country house located outside Ellesborough and around 40 miles (65 kilometers) northwest of the capital. The 16th-century mansion was previously used British premiers as a retreat for the past century.

Slack denied that the administration had downplayed the severity of Johnson's condition.

Johnson was admitted to the hospital on April 5 after his condition aggravated. He received oxygen in the ICU and was not put onto a ventilator.

According to his spokesman, being tested before leaving the hospital was "standard practice."

The prime minister has been reunited with Carrie Symonds, his pregnant fiancée.

Johnson lauded the National Health Service in a video address to the U.K., saying they "saved my life, no question."

He tweeted, "I thank you because so many millions and millions of people across this country have been doing the right thing, millions going through the hardship of self-isolation faithfully, patiently, and with thought and care for others as well as themselves."

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According to the mother of a nurse who took care of Johnson during his ICU treatment, her daughter found the experience to work for him "surreal."

He required a "significant level of specialist treatment" at the worst points of his ordeal against the virus, his spokesman said.

Slack added, "So, I think it was clear from the moment the Prime Minister was moved to intensive care that his condition had worsened."

Partner Symonds also expressed gratitude for the "magnificent" NHS hospital staff as she was also ill with the virus.

The prime minister declared on March 27 that he had contracted the coronavirus and was suffering from "mild symptoms."

Ten days later, Johnson tweeted that he will enter a hospital "for some routine tests as I'm still experiencing coronavirus symptoms."

It is unclear when the prime minister plans to return to full-time work.

Contrary to statements from 10 Downing Street that depicted Johnson "in good spirits," both he and Symonds hinted at more bleak outlooks, with his fiancée dubbing it a "very dark" week.

Raab has been spearheading the administration's daily meetings on the coronavirus, but a verdict is due on Thursday when the country's 3-week-old lockdown is reviewed.

Slack noted that Johnson is not fulfilling government duties and is focusing on his recuperation.

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