NICOLA Sturgeon warned that coronavirus “is still a real threat” as figures revealed the first consistent Covid-related increase in hospital admissions for months.

The First Minister said officials were looking “very carefully” at what appears to be a rise in cases of the infection in recent weeks, as the number of people being treated in hospital with the virus climbed by 15 since Friday.

Public health expert Professor Linda Bauld said there was now “some cause for concern”.

“If it was just new cases then it would be far less of a cause for alarm,” she added.

Ms Sturgeon confirmed yesterday that the number of people being treated for Covid in hospital had risen by five, to 270.

That is up from 255 on Friday, following an increase of five admissions on Saturday and a further five on Sunday. All patients have tested positive for the virus.

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It is the first time since April that an increase in admissions has been sustained over three or four consecutive days, albeit in much smaller numbers than during the peak of the outbreak when hundreds of patients were being admitted to hospital every day.

The increase in admissions also comes after four weeks of fairly steady rises in new cases.

Virus incidence bottomed out during the week ending July 8, when only 50 new cases were detected.

In the past week, 159 people have tested positive - the highest since early June.

Ms Sturgeon said the figures should be a warning to "pay attention" to the risk of transmission, which she said had not gone away.

"We know that we are possibly seeing a bit of an uptick is cases," said the First Minister.

"Most of those at the moment, we think, are associated with clusters and outbreaks - not necessarily an uptick in broader community transmission.

"But we're looking at that very, very carefully.

"So at the moment all of the data leads me back to the same point: this virus is still a real threat, and it's still out there."

She added: "We shouldn't get carried away at the moment, and overstate things, but equally, the data in Scotland and across the UK, and some of what's happening worldwide - if we're not hearing these warnings, then we're not paying attention.

"We've got to pay attention to the fine changes in all of this so we can try to act before it gets out of control."

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On Friday, Ms Sturgeon said that around half of new Covid cases detected in Scotland last week were among Scots aged 20-39, leading National Clinical Director Professor Jason Leitch to say that young people might have "taken their foot off the brake just a little too early"

Younger people are less likely to become unwell - or even to develop symptoms - from catching the virus, but can still spread it to people who are more at risk.

In Spain, prior to May 11 those aged 15 to 29 accounted for just five per cent of the country's Covid cases; since May 11 they have accounted for more than 20%.

Prof Bauld, the Bruce and John Usher Professor of Public Health at Edinburgh University's Usher Institute, said: "It's pretty apparent from other countries that most of the cases post-lockdown have come from younger people who are moving around more, but less likely to have symptoms or to become very unwell.

"However, they will pass it on to others and some of them of course may well become unwell.

"So we would expect to see when cases go up - even in the small numbers we're seeing now - that that is going to translate into some hospital admissions.

"So I think there is some cause for concern. If it was just new cases then it would be far less of a cause for alarm.

"But if more people are going into hospital, hopefully what we won't see are more of them going into ICU.

"Because if we start to see that creep up, even in small numbers, then we are going to see some deaths again."

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There are currently four Covid patients in intensive care, up from two a week ago.

The number of Covid tests being carried out in Scotland has increased substantially in the past month, from around 32,000 to 72,000 a week, but Prof Bauld said the increase in new cases appeared to be genuine rather than false positives.

She added that even with a resurgence, if cases were concentrated among younger Scots with elderly care homes better prepared with PPE, testing and improved infection control then mortality from Covid should still be lower than it was during the first phase of the pandemic.

"If we have care homes in a better position this time we're not going to see people dying in the same proportions," said Prof Bauld.

"There's several reasons why we might see fewer deaths in the short-term, but one of them will be it's people who are less vulnerable who are testing positive."