Anyone with a cough or cold will soon be told to self-isolate for a week as Britain prepares for a significant rise in coronavirus cases.
As the number of cases in the UK increased to 319 – including five deaths – the chief medical officer said the public would be asked to take extra steps to prevent the spread of disease.
Health officials are expected to advise pensioners in particular to limit their social contact, but stressed on Monday night that the country had not yet reached that point.
It came as Giuseppe Conte, the Italian Prime Minister, extended lockdown measures imposed in the north on Sunday to the entire country. Only those with a certifiable work or health emergency will be permitted to travel, while all sporting events and public gatherings have been suspended until at least April 3.
In a televised address, Mr Conte urged Italians to stay at home, with the move coming after the country’s coronavirus death toll soared by 97 to 463 on Monday.
Spain announced the closure of all public schools in the Madrid region for at least two weeks, while Franck Riester, France’s culture minister, was diagnosed with the virus.
Professor Chris Whitty, the chief medical officer for England, said that within 10 to 14 days the Government would issue advice asking anyone with a cough or cold to stay at home. He said infections were expected to “increase really quite fast”.
The advice – which could involve millions of people being asked to self-isolate without tests – would apply to all those with respiratory infections, including minor coughs and fevers.
On Monday night, health officials said taking such measures at the right time could push down the peak number of cases by half and cut deaths by almost a third.
Boris Johnson, the Prime Minister, said it was “absolutely critical” to take the right decisions at the right time, warning that taking certain measures too early could prove “counter-productive”.
Mr Johnson said he had stopped shaking hands and suggested that, while handwashing was more important, avoiding a handshake gave people a “subliminal” reminder about their hygiene.
His advisers said asking people to self-isolate before the virus was in common circulation could backfire and mean the public was unlikely to comply with measures when they were truly needed.
Sir Patrick Vallance, the chief scientific adviser, said those who have “the sniffles” now were unlikely to have coronavirus – a situation that will rapidly change.
Prof Whitty said: “We are expecting the numbers to increase, initially slowly but really quite fast after a while, and we have to catch it before the upswing begins.
“We are now very close to the time, probably in the next 10 to 14 days, where we should say everybody who has even minor respiratory tract infections or a fever should be self-isolating for seven days afterwards.”
Mr Johnson said he believed the UK could rise to the challenge posed by coronavirus, adding: “While it is absolutely critical in managing the spread of this virus that we take the right decisions at the right time based on the latest and the best evidence, so we mustn’t do things which have no or limited medical benefit, nor things which could turn out actually to be counter-productive.
“There is no hiding from the fact that the coronavirus outbreak will present significant challenges for the UK, just as it does in other countries. But if we continue to look out for one another, to pull together in a united and national effort, I have no doubt that we can and will rise to that challenge.”
Hospitals have also been ordered to carry out coronavirus tests on all patients with respiratory infections in order to limit the spread of the virus within wards.
It comes as two more people in their 70s were killed by the outbreak, taking the UK death toll to five. Both had underlying health conditions, with one dying at the Royal Wolverhampton Hospital and the other at St Helier Hospital, in south London.
The Government’s scientific advisory group for emergencies is expected to meet on Tuesday and advise on the introduction of “social distancing” restrictions, which could come as soon as this week. It follows a meeting of the Cobra emergency committee on Monday.
Mr Johnson said: “Our plan sets out what we are prepared to do, and we’ll make the right choices of which action to pursue at the right moment.
“The scientific advice is clear – acting too early creates its own risks, so we will do what is right to keep people safe. Guided by the science, we’ll act at the right time and we’ll be clear and open about our actions and the reasons for them.”
Meanwhile, a secondary school pupil in Rugby was diagnosed with the virus more than 14 days after returning from Italy and staying in self-isolation, and University Hospital Southampton closed its surgical high-dependency unit to new admissions after a staff member tested positive.
The France versus Ireland Six Nations rugby match, due to be held in Paris on Saturday, was postponed on the advice of national authorities. France, where more than 1,100 cases have been recorded and 19 people have died, announced a ban on events of more than 1,000 people.
But Oliver Dowden, the UK’s Culture Secretary, said cancelling sports events and shutting museums and galleries due to coronavirus would be “premature”.
Downing Street defended its response in comparison with more drastic action being taken elsewhere, and Mr Johnson’s official spokesman said: “It’s not for me to speak on behalf of other countries. The guiding principle for the Prime Minister is that he will take the guidance of his medical and scientific advisers.”
While some other European countries are cancelling mass gatherings or limiting the number of people who can attend big events, Mr Dowden said there are “no plans” for Britain to follow suit.
He insisted the Government was following the advice of health officials and, while the situation is kept under review, there is currently “no need” to cancel large events or for people to avoid public places.