The first case of coronavirus transmitted within the community has been detected in Scotland, amid warnings that the UK has “a window of days” to prepare for the worst. 

Scotland’s Chief Medical Officer Dr Catherine Calderwood confirmed that one of the nine new cases identified in Scotland was in a patient whose infection could not be traced either to travel or contact with another known case. 

Evidence of community transmission was expected, but it is considered a key tipping point in the spread of the virus. 

It came as the World Health Organisation (WHO) officially declared coronavirus a global pandemic. 

Dr Calderwood said: “We have identified the first case of community transmission in Scotland, which is unrelated to contact or travel.

“This was identified through our enhanced surveillance scheme. It is important to emphasise that we are still in the containment phase.

“This case was to be expected and highlights the importance of the additional measures we have put in place to identify positive cases beyond self-identification.”

A total of 36 cases of coronavirus Covid-19 have now been confirmed in Scotland, among a UK total of 460 with eight dead. 

Across the UK the number of patients diagnosed with the virus has doubled in four days, with signs that transmission is accelerating. The most recent daily increase of 83 new cases is the sharpest spike to date. 

In Scotland, cases have been confirmed in all but four health board regions: Highland, Dumfries and Galloway, Orkney and the Western Isles. The highest number of cases –eight – has been detected in Lothian. 

It came as health bosses outlined plans to deploy thousands of student nurses and medical students to bolster frontline NHS resources for a surge in seriously ill patients. 

Scotland’s Health secretary Jeane Freeman said NHS modelling indicated that the virus could result in an absence rate of between 25 per cent and 30% among health service workers. 

NHS staff are at “greater risk” of contracting the disease as a result of caring for infected patients, even with protective equipment.

To help cope with staff shortages, Ms Freeman said the NHS is looking at how recently retired staff can return to work, as well as how those who are almost qualified can help.

Ms Freeman said there are “something like 3,000 available nursing students” as well as medical students in their fifth and final year of university study.

She said they could play an “important role” in supporting the NHS, but would only be asked to do skills within their training.

NHS England also unveiled plans to parachute up to 18,000 third-year undergraduate nurses onto the frontline as paid volunteers. 

Sir Simon Stevens, chief executive of NHS England, said the UK would be “shortly entering a phase where we are going to be taking measures at the population level to spread the number of cases over a long period of time” to lessen the impact on the NHS. He added: “We have a window of days, a few weeks, to get ourselves prepared.”

Ms Freeman also admitted that Scottish Government plans to increase the number of available hospital beds, including doubling Scotland’s intensive care capacity, would be achieved partly by cancelling and delaying routine operations such as hip and knee replacements. 

NHS bosses have insisted that urgent work such as cancer surgery and chemotherapy would not be affected. Scotland has around 13,100 acute beds and 275 in intensive care units, but the Government has estimated that a worst-case scenario could see around 170,000 requiring critical care. 

Ms Freeman said: “We have active work going on looking at how we can increase the number of beds available in our hospital settings, doubling the number of intensive care units that we have and equipping them and staffing them. You start to make difficult decisions about NHS care that is critical to life – that would be cancer treatment, transplants, maternity care –from NHS care that is not critical to life. That is some of our elective work, the replacements of knees, hips and so on.

“You start to scale down the non-critical in order to free up the space for the critical. 

“That is where you get additional bed space but you also can get additional intensive care space.”

There were also warnings that the Houses of Parliament could exacerbate the epidemic in the wake of health minister Nadine Dorries’ diagnosis with Covid-19. She was self-isolating at home as both her offices were sealed off and one of her staff fell ill.

Glasgow MP Carol Monaghan said: “On top of the 650 MPs and the 800 peers, it is estimated that up to 6,000 people work on the parliamentary estate, with 3,000 more visiting daily. 

“Each week we are crammed into a pungent chamber that is too small to accommodate everyone, and find ourselves up close and personal in crowded voting lobbies.  

“After our week in Westminster we travel back to every part of the UK to meet local constituents and organisations. Anything we may have picked up in these confined conditions will be taken with us, and by continuing to operate Parliament in this manner, we could be creating 650 vectors for this virus.”

It comes as a petition to close schools and colleges across the UK exceeded 260,000 signatures, and Europa League clashes between Spanish and Italian sides Sevilla and Roma, and Inter Milan and Getafe, were postponed in a bid to curb infections.

The Premier League also called off its first match over fears that Arsenal players – who were due to face Manchester City – might have been exposed to the virus when Nottingham Forest owner, Evangelos Marinakis, who has tested positive for the virus, visited the Emirates stadium.