The coronavirus R rate across the UK has risen to at least 1 in all regions, various estimates have said today.
The value shows the average number of people each COVID-19 positive person goes on to infect, and is hard to measure exactly.
When it is above 1, the virus is spreading.
Today, government data showed that authorities estimate the UK’s R number is between 1 and 1.2.
But two other estimates have also been given. One study from Imperial College London has said R could be 1.7.
This is how each of those different estimates have come about.
The government’s estimate
The official estimate that the UK’s R is between 1 and 1.2 was released on Friday, following a week of new daily infections totalling more than 2,000 a day.
The government says it uses a “range of data” to estimate R and the virus’s growth rate.
It uses epidemiological data such as admissions to hospital and intensive care, as well as deaths. This can mean a three week lag because of the time it takes for a person to become infected and later end up in hospital after developing complications.
Surveys assessing people’s behaviour are also used, which can be quicker to feed into new R rates but rely on self-reported behaviour and make assumptions about how the information relates to COVID-19’s spread.
Household infection surveys, where people are given swab tests, also feed into the data.
Different models are then produced and the government uses those to produced an estimated range of the R number, with the true value likely to be somewhere within that range.
England’s cases have been doubling every seven to eight days since 22 August, a study has suggested.
Scientists at Imperial College London examined test results from more than 300,000 volunteers between 24 July and 7 September – the country’s largest study into the coronavirus outbreak.
They believe that 13 in 100,000 people in England had the coronavirus, compared to four in every 10,000 between 24 July and 11 August.
The study suggests R is at 1.7 – higher than the official estimate.
The University of Reading’s Dr Simon Clarke said: “If the R number is as high as 1.7, as this data suggests, then we could be at risk of being almost back at square one in terms of our ability to contain the virus.
“This is a massive blow to the government’s strategy to contain the spread of COVID-19.”
The government has reacted to the rise in cases this week by banning gatherings of more than six in England.
The Mirror reported earlier on Friday that R is 1.3 in England, 1.2 in Scotland and Wales and 1.1 in Northern Ireland, based on a study.
It said this information came from unofficial data from a government-funded app by health science firm Zoe in which users can self-report coronavirus symptoms. Analysis is then provided by King’s College London.
The Mirror said the study suggested 35,248 people have symptomatic COVID-19, up from just over 22,000 last week, with the uk averaging 3,610 cases each day in the two weeks to 6 September.
The 1.3 estimate for England is just above the government’s figure for the same country, which is at most 1.2.
Coronavirus: what happened today
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