Number of people thought to be infected with Covid-19 revised down
Scotland’s estimated number of people infected by Covid-19 has been revised down by more than half after the First Minister revealed the country’s R-number signifying the reproduction rate had fallen.
The critically important figure is the rate at which an infected person transmits the virus to others, so if the R-number was two then for each carrier two new people would be infected – but currently the estimate is between 0.6 and 0.8.
Nicola Sturgeon said today this was positive and meant the figure continued to move in the right direction, as previously it hovered between 0.7 and 0.9. She warned, however, that this was high enough to allow the virus spike again.
She also revealed that the current estimate for people carrying the virus in Scotland is 4500 – previously it had been thought that it was 11,500, which is now considered to be an overestimate.
That news allows a further easing of the lockdown for the building industry so that with the proper health and safety planning it can move to the next step of the plan and allow workers to return to sites gradually.
The move will not allow the sector to operate at full capacity but will enable some work to be done in anticipation of the start of phase two – which is expected to be announced one week today by the First Minister.
Ms Sturgeon said: “The R-number shows the rate at which this virus is reproducing, so if the R-number is above one then every person with the virus will infect more than one other person and the virus will spread exponentially. But if the R-number is below one then the number of people with the virus will fall.
“We estimate the R-number in Scotland, as of last Friday [June 5], was between 0.6 and 0.8 – that is a lower estimate than for two weeks ago when we calculated that the number was likely to be between 0.7 and 0.9. So under that estimate we expect that the virus will continue to decline.
“In addition, we estimated last Friday that 4500 people in Scotland had the virus and were infectious – our previous estimate for May 29 was that 11,500 people were likely to be infectious.
We have been reassessing our estimates for previous weeks based on the latest figures available to us.
“Now that sounds like a very big decline, so it's worth stressing that we don't actually think the number of infectious people has more than halved in just one week – but what has been happening is that we have been reassessing our estimates for previous weeks based on the latest figures available to us.
“In short, it is likely that the 11,500 was an overestimate – not that the number has halved in a single week. These latest estimates reflect the encouraging data that we have seen in the last couple of weeks and there is no doubt, looking at all of this data, that we're making very real progress in combating and suppressing the virus.
“As always it's important that I inject a note of caution. We don't yet take account of the phase one changes and we need to continue to monitor any impact from that carefully.
“Secondly, the number of people who we estimate are infectious is certainly smaller than it was but it is also still large enough to make the virus take off rapidly again if the R-number was to go much above one – so we need to celebrate the progress but continue to be careful and cautious.
“A week today we will have a further review of the lockdown restrictions. I am currently very hopeful that at that point we will be able to lift some further restrictions. We may not be able to do everything in phase two but I hope we can do at least some of that."
