Health officials are desperately trying to find coronavirus carriers unwittingly spreading the deadly illness.
They fear the individuals have only mild symptoms and do not realise they are infected. The crisis deepened yesterday when 13 new cases were reported – bringing the number in the UK to 36.
The total has almost tripled in four days with the virus now reaching all corners of the British Isles.
But the South East is on the front line with experts trying to identify the sources of outbreaks in Essex, Surrey and West Sussex.
Five of the latest victims caught coronavirus within the UK – and not abroad – meaning it may already be too late to head off an epidemic.
Officials have not ruled out drastic measures such as locking down cities, closing schools, recalling retired doctors and banning large gatherings.
As Boris Johnson admitted the virus was a 'significant challenge':The Society for Acute Medicine said a major outbreak would put the NHS under 'immense stress' with operations cancelled;The World Health Organisation advised over-60s to avoid crowded areas to protect themselves;Scotland recorded its first case of coronavirus;The Louvre in Paris closed its doors and the French health minister advised against kissed greetings;Stock markets were braced for further falls this morning.
Earlier today, the PM hailed frontline NHS staff as the UK's 'greatest asset' in the face of the coronavirus outbreak. Pictured: Mr Johnson during a visit to a laboratory in PHE's National Infection Service
Manchester City fans wear face masks before watching their team take on Aston Villa at Wembley. Manchester and London both confirmed cases today
The global coronavirus death toll has hit 3,000 following a sudden spike in Italian cases.
Five fatalities were announced in Italy today, taking its death toll to 34 as infection continues to cripple the country's northern regions.
Total patient numbers rose to 1,694 after the Civil Protection Agency revealed roughly 500 fresh positive tests this evening - an alarming 50 per cent climb in just 24 hours.
The outbreak is the second largest outside of mainland China and is steadily seeping across the continent, despite the infection hotbeds of Lombardy and Veneto on lock-down.
Ministers in Rome have taken drastic measures to firefight the epidemic, including scrapping public events and erecting police checkpoints around the 11 contaminated towns.
But despite the travel freeze from the virus-hit areas, where 50,000 citizens are in quarantine, cases scattered across Europe have been traced back to Italy.
Of the 13 new patients announced in the UK, seven had recently returned from Italy.
While coronavirus can be fatal – and roughly one in seven victims suffer very serious symptoms – for many the impact can be mild. This means victims could brush aside their symptoms, assuming it is a common cold.
Ministers had hoped they could contain the virus by tracking and isolating cases as soon as the victims returned from high-risk areas. But with 67 countries affected, this is becoming impossible.
Health Secretary Matt Hancock admitted it was inevitable that coronavirus would become endemic – the medical term for a virus becoming permanently resident in a country. He insisted the Government was still trying to do all it could to contain and isolate the virus.
If that fails the next stage will be to try to delay its peak until the summer months, when pressure on the NHS should be lower.
Professor Jonathan Ball of the University of Nottingham said spread of the virus 'marked a new chapter for the UK'.
He added: 'This is a virus that frequently causes symptoms very similar to mild flu or a common cold, and it's easily transmitted from person to person. This means it can easily go under the radar.
'It has a high likelihood of becoming one of the many respiratory viruses that circulate around the globe, peaking in winter months infecting those who are susceptible.'
Mr Hancock refused to rule out the scenario of entire cities being locked down – as has been done in China – although he stressed he wanted to avoid this in order to minimise disruption.
Announcing a 'war room battle plan', he said 'population-distancing measures' may become necessary – such as banning public gatherings, cancelling football matches and closing schools.
Mr Hancock said everyone had a duty to help stop the spread of coronavirus by regularly washing their hands.
St Mary's School in Tetbury (pictured) has confirmed a member of staff has tested positive for Covid-19. The case in the Cotswolds was among three identified on Saturday
Pictured: People wearing face masks ahead of the St David's Day Parade in Cardiff today as fears continue to sweep Britain while the coronavirus crisis unfolds
Markets were braced for futher falls today after a tenth was wiped