Coronavirus: What does a rise in UK cases really mean?

Scientists who have been advising the government during the coronavirus pandemic are reminding people that hand washing and social distancing are still really important ways to stop the spread of Covid-19.

They are urging people to start taking more care because of an increase in cases across the UK.

The government said 2,948 UK cases were recorded on Monday, that follows 2,988 new cases being announced on Sunday, which was the highest figure since May.

England's deputy chief medical officer, Professor Jonathan Van Tam, said: "People have relaxed too much."

The government's health secretary, Matt Hancock, said it was "so important that people take their responsibilities seriously, and people don't become relaxed about this virus".

Although the rise in cases can be worrying, so far it hasn't meant more people getting seriously ill and health experts are working hard to make sure that doesn't change.

Why are cases rising?

With lockdown rules gradually easing, businesses reopening and school starting again, more people are mixing.

The more someone goes out and does more things, the more people they will come into contact with who might have the virus.

In the same way, some people could be carrying the virus and have no symptoms, so going out and seeing more people could spread the virus without them knowing.

When looking at the dangers of people catching coronavirus, the government looks at something called the R number. That's the number of people that one infected person will pass the virus on to, on average.

So if the R number is one, that means one person with the virus will on average infect just one other person.

However, if the R rate is higher - at say three - that means one person with the virus passes it on to three other people.

The government says that at the moment the R number is "above one" and last week a third of all cases in England were recorded in people aged between 20 and 29.

That suggests it's younger people who are mixing more and even though being young means you're less likely to become ill, anyone can pass the virus on.

Prof Van Tam says that among that age group, the rise in cases has been seen most in those aged between 17 and 21 and there are concerns that young people who have the virus can pass it on to their parents, grandparents and other vulnerable people.

"The fact that 17 to 21-year-olds are not becoming ill means they are lucky, but they also forget because the disease is not severe for them that they are potent spreaders," Prof Van Tam said.

"It's a mistake for people to think this infection is over," Professor Carl Heneghan from University of Oxford told the BBC.

"The virus is still circulating and if we lose our vigilance, rates will go up. I think we need simple clear messages to the public which stress the importance of hand washing and social distancing."

There's more testing now

There's also a lot more testing happening now than at the worst point of the pandemic during lockdown. Around 170,000 tests are being carried out every day.

When there was less testing, there would have still been people who had coronavirus without knowing - so they weren't added to the numbers you heard on the news.

But now new speedy tests are being developed and the process of getting tested and getting results back has improved over time.

Also, the more people you test, the more likely you are to find new cases which is another reason the numbers of people with the virus can be higher.

But more cases has not meant more people in hospital

The rise in confirmed cases since July hasn't so far meant that more people have been admitted to hospital because of the virus.

In fact, the number of patients in hospital who have coronavirus has been falling for months.

And if you do end up in hospital, doctors and nurses now have a better understanding of how to treat the virus to stop people becoming severely ill.

Ways to stop the virus spreading

The government is saying things like social distancing, washing hands and rules around face coverings, are still really important to follow.

The health secretary Mr Hancock said the UK wanted to avoid a second wave which has been seen in France and Spain, where things got better before getting worse again.

"That hasn't happened here yet," he said. "And if people follow the social distancing rules, then we can stop that from happening here."

For those who are out doing things and coming into contact with more people, there are test and trace systems, quarantine rules when returning from holiday, and other measures, so if someone does have coronavirus they're more likely to find out and less likely to spread it.

What's being done in places with lots of cases?

Caerphilly county is the first area of Wales to be put into local lockdown

Scientists and experts monitor numbers and data constantly so the government can act quickly to stop the spread of the disease.

Tougher rules can be put in places where there are more cases to try and bring that number down, this is often called a 'local lockdown'.

In Wales, Caerphilly county has become the first part of the country to be placed under stricter lockdown rules.

From 6pm on Tuesday 8 September no-one will be allowed to leave or enter the area, without good reason.

Family and friends living apart will no longer be able to meet indoors, or stay overnight. It comes after a spike in cases, with 98 people testing positive in a week.

Extra lockdown rules are still in place in parts of Greater Manchester, east Lancashire and West Yorkshire, where people have been told they aren't allowed to meet anyone from a different households indoors.

And in Bolton in Greater Manchester, restaurants, cafes and pubs are only allowed to serve takeaway food and have to close by 10pm each night.

There are also restrictions in Glasgow city, West Dunbartonshire and East Renfrewshire in Scotland.